tag:theconversation.com,2011:/us/topics/daylight-saving-time-50635/articlesDaylight saving time – The Conversation2024-03-04T13:36:47Ztag:theconversation.com,2011:article/2245972024-03-04T13:36:47Z2024-03-04T13:36:47ZCould the days of ‘springing forward’ be numbered? A neurologist and sleep expert explains the downside to that borrowed hour of daylight<figure><img src="https://images.theconversation.com/files/579007/original/file-20240229-24-zwzuqp.jpg?ixlib=rb-1.1.0&rect=16%2C8%2C5557%2C3648&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">While that 'extra' hour of sunlight in the evenings can be exhilarating, it comes with significant health trade-offs.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/daylight-saving-time-notepad-with-text-spring-royalty-free-image/1365468815?phrase=daylight+saving+time&adppopup=true">Anna Blazhuk/Moment via Getty Images</a></span></figcaption></figure><p>As people in the U.S. prepare to set their clocks ahead one hour on Sunday, March 10, 2024, I find myself bracing for the annual ritual of <a href="https://www.inquirer.com/news/standard-time-daylight-saving-time-clock-change-sleep-20201031.html">media stories</a> about <a href="https://qz.com/1114163/daylight-saving-time-dst-is-incredibly-disruptive-heres-how-to-reset/">the disruptions to daily routines</a> <a href="https://doi.org/10.5664/jcsm.8780">caused by switching from standard time</a> to daylight saving time. </p>
<p>About one-third of Americans say they don’t look forward to these twice-yearly time changes. And nearly two-thirds <a href="https://today.yougov.com/topics/politics/articles-reports/2021/11/04/daylight-saving-time-americans-want-stay-permanent">would like to eliminate them completely</a>, compared with 17% who aren’t sure and 21% who would <a href="https://docs.cdn.yougov.com/etwjvohrxx/Daylight_Saving_Time_Toplines_Crosstabs.pdf">like to keep moving their clocks back and forth</a>. </p>
<p>But the effects go beyond simple inconvenience. Researchers are discovering that “springing ahead” each March is connected with serious negative health effects, including an uptick in <a href="https://doi.org/10.3390/jcm8030404">heart attacks</a> and <a href="https://doi.org/10.5664/jcsm.4938">teen sleep deprivation</a>. In contrast, the fall transition back to standard time is not associated with these health effects, as my co-authors and I explained in a <a href="https://doi.org/10.1001/jamaneurol.2019.3780">2020 commentary</a>.</p>
<p>I’ve studied the pros and cons of these twice-annual rituals for more than five years as a <a href="https://scholar.google.com/citations?user=ZddlKEoAAAAJ&hl=en">professor of neurology and pediatrics</a> and the director of Vanderbilt University Medical Center’s sleep division. It’s become clear to me and many of my colleagues that the transition to daylight saving time each spring affects health immediately after the clock change and also for the nearly eight months that <a href="https://www.cnn.com/2022/11/06/health/permanent-daylight-savings-health-harms-wellness/index.html#">Americans remain on daylight saving time</a>.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/NnlhgasgQYc?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Washington is one of the states where legislators are pushing for permanent standard time.</span></figcaption>
</figure>
<h2>Why our bodies are thrown off by DST</h2>
<p>Americans are split on whether they <a href="https://today.yougov.com/topics/politics/articles-reports/2021/11/04/daylight-saving-time-americans-want-stay-permanent">prefer permanent daylight saving time</a> or <a href="https://apnorc.org/projects/dislike-for-changing-the-clocks-persists/">permanent standard time</a>. But a <a href="https://savestandardtime.com/current/">growing number of states</a> are supporting permanent standard time. </p>
<p>However, the two time shifts – jolting as they may be – are not equal. Standard time most closely approximates natural light, with the sun directly overhead at or near noon. In contrast, during daylight saving time from March until November, the clock change causes natural light to be present one hour later in the morning and one hour later in the evening according to clock time.</p>
<p>Morning light is essential for helping to set the body’s natural rhythms: It <a href="https://doi.org/10.1038/s41598-018-36791-5">wakes us up and improves alertness</a>. Morning light also boosts mood – light boxes simulating natural light are prescribed for morning use <a href="https://doi.org/10.1001/archpsyc.55.10.890">to treat seasonal affective disorder</a>.</p>
<p>Although the exact reasons why light activates us and benefits our mood are not yet known, this may be due to light’s effects on <a href="https://doi.org/10.1080/10253890.2020.1741543">increasing levels of cortisol</a>, a hormone that <a href="https://doi.org/10.1038/s41574-019-0228-0">modulates the stress response</a>, or the effect of <a href="https://doi.org/10.1038/s41598-018-36791-5">light on the amygdala</a>, a part of the brain involved in emotions.</p>
<p>Adolescents also may be <a href="https://theconversation.com/school-start-times-and-screen-time-late-in-the-evening-exacerbate-sleep-deprivation-in-us-teenagers-179178">chronically sleep-deprived due to school</a>, sports and social activities. For instance, many <a href="https://nces.ed.gov/pubs2020/2020006/index.asp">children start school around 8 a.m.</a> or earlier, which means that during daylight saving time they get up and travel to school in pitch darkness.</p>
<p>The body of evidence makes a good case for adopting permanent standard time nationwide, as I testified at a <a href="https://democrats-energycommerce.house.gov/committee-activity/hearings/rescheduled-hearing-on-changing-times-revisiting-spring-forward-fall">March 2022 Congressional hearing</a> and argued in a <a href="https://doi.org/10.1093/sleep/zsac236">recent position statement</a> for the Sleep Research Society. The American Medical Association recently <a href="https://www.ama-assn.org/press-center/press-releases/ama-calls-permanent-standard-time">called for permanent standard time</a>. And in late 2022, <a href="https://www.timeanddate.com/news/time/mexico-abolishes-dst-2022.html#">Mexico adopted permanent standard time</a>, citing benefits to <a href="https://thehill.com/policy/international/3708301-mexicos-senate-votes-to-end-daylight-saving-time-for-most-of-the-country/">health, productivity and energy savings</a>. </p>
<figure class="align-center ">
<img alt="An illustration of two clocks depicting Daylight Savings Time changes: Fall backward, and spring forward." src="https://images.theconversation.com/files/446653/original/file-20220215-13-1d96ozk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/446653/original/file-20220215-13-1d96ozk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=360&fit=crop&dpr=1 600w, https://images.theconversation.com/files/446653/original/file-20220215-13-1d96ozk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=360&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/446653/original/file-20220215-13-1d96ozk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=360&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/446653/original/file-20220215-13-1d96ozk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=452&fit=crop&dpr=1 754w, https://images.theconversation.com/files/446653/original/file-20220215-13-1d96ozk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=452&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/446653/original/file-20220215-13-1d96ozk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=452&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">In 2024, clocks spring forward one hour at 2 a.m. on Sunday, March 10. They fall back at 2 a.m. on Sunday, Nov. 3.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/illustration/daylight-saving-time-fall-backward-and-royalty-free-illustration/1356689682?adppopup=true">iam2mai/iStock via Getty Images Plus</a></span>
</figcaption>
</figure>
<p>The biggest advantage of daylight saving time is that it provides an extra hour of light in the late afternoon or evening, depending on time of year, for sports, shopping or eating outside. However, exposure to light later into the evening for almost eight months during daylight saving time comes at a price. This extended evening light delays the brain’s release of melatonin, the hormone that promotes drowsiness, which in turn interferes with sleep and <a href="https://doi.org/10.1093/sleep/zsac236">causes us to sleep less overall</a>.</p>
<p>Because puberty also causes <a href="https://www.neurologylive.com/view/teenage-circadian-rhythm">melatonin to be released later at night</a>, meaning that teenagers have a delay in the natural signal that helps them fall asleep, adolescents are <a href="https://dx.doi.org/10.5664/jcsm.4938">particularly susceptible to sleep problems</a> from the extended evening light. This shift in melatonin during puberty lasts into our 20s.</p>
<h2>The ‘western edge’ effect</h2>
<p>Geography can also make a difference in how daylight saving time affects people. One study showed that people living on the western edge of a time zone, who get light later in the morning and later in the evening, <a href="https://doi.org/10.1016/j.jhealeco.2019.03.007">got less sleep</a> than their counterparts on the eastern edge of a time zone. </p>
<p>This study found that western-edge residents had higher rates of obesity, diabetes, heart disease and <a href="https://theconversation.com/breast-cancer-risk-higher-in-western-parts-of-time-zones-is-electric-light-to-blame-85803">breast cancer</a>, as well as lower per capita income and higher health care costs. Other research has found that <a href="https://doi.org/10.1158/1055-9965.EPI-16-1029">rates of certain other cancers are higher</a> on the western edge of a time zone. </p>
<p>Scientists believe that these health problems may result from a combination of <a href="https://doi.org/10.3389/fphys.2019.00944">chronic sleep deprivation and “circadian misalignment</a>.” Circadian misalignment refers to a mismatch in timing between our biological rhythms and the outside world. In other words, the timing of daily work, school or sleep routines is based on the clock, rather than on the sun’s rise and set. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/84aWtseb2-4?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">This video takes a deeper dive – all the way back to 1895 – into the history of daylight saving time.</span></figcaption>
</figure>
<h2>A brief history of daylight saving time</h2>
<p><a href="https://blogs.loc.gov/teachers/2017/03/world-war-i-and-daylight-savings-time/">Congress instituted year-round daylight saving time</a> during World War I and World War II, and <a href="https://www.mercurynews.com/2016/10/30/the-year-daylight-saving-time-went-too-far/">once again during the energy crisis</a> of the early 1970s. But the popularity of year-round daylight saving time fell from 79% to 42% after it went into effect in January 1974, largely due to <a href="https://www.washingtonian.com/2022/03/15/the-us-tried-permanent-daylight-saving-time-in-the-70s-people-hated-it/">safety concerns about children going to school in the dark</a>. </p>
<p>The idea at that time was that having extra light later into the afternoon would save energy by decreasing the need for electric lighting. This idea has since been <a href="https://doi.org/10.1016/j.jebo.2014.03.012">proved largely inaccurate</a>, as heating needs may increase in the morning in the winter, while air conditioning needs can also increase in the late afternoon in the summer.</p>
<p>After World War II, designating the start and end dates for daylight saving time fell to state governments. Because this created many railroad scheduling and safety problems, however, Congress passed the <a href="https://www.transportation.gov/regulations/time-act#">Uniform Time Act in 1966</a>. This law set the nationwide dates of daylight saving time from the last Sunday in April until the last Sunday in October. In 2007, <a href="https://www.bts.gov/geospatial/daylight-savings-time">Congress amended the act</a> to expand the period in which daylight saving time is in effect from the second Sunday in March to the first Sunday in November – dates that remain in effect today.</p>
<p>But the Uniform Time Act does allow states and territories to opt out of daylight saving time. Arizona and Hawaii are on permanent standard time, along with Puerto Rico, the U.S. Virgin Islands, Northern Mariana Islands, Guam and American Samoa. </p>
<h2>A shifting landscape</h2>
<p>As of March 2024, <a href="https://savestandardtime.com/current/">17 states have passed laws</a> to adopt year-round daylight saving time. But federal law requires that they need to wait for Congress, and in some cases also neighboring states, to act. More than two dozen states <a href="https://www.sleepfoundation.org/sleep-news/latest-updates-daylight-saving-time-legislation-change#what-is-the-status-of-state-level">introduced legislation related to the clock change in 2023</a>, but no laws were passed. </p>
<p>Meanwhile, proposed legislation and resolutions for <a href="https://savestandardtime.com/current/">permanent standard time have increased</a> from 15% in 2021 to 37% in 2024. </p>
<p>In March 2022, the U.S. Senate <a href="https://www.congress.gov/bill/117th-congress/senate-bill/623">passed the Sunshine Protection Act </a> in a bid to <a href="https://www.reuters.com/world/us/us-senate-approves-bill-that-would-make-daylight-savings-time-permanent-2023-2022-03-15/">make daylight saving time permanent</a>. But the House did not move forward with this legislation. Florida Sen. Marco Rubio <a href="https://thehill.com/homenews/nexstar_media_wire/3880009-bill-to-make-daylight-saving-time-permanent-reintroduced-in-congress/">reintroduced the bill</a> on March 1, 2023, but <a href="https://www.congress.gov/bill/118th-congress/senate-bill/582/all-info#">this bill has not progressed</a>. </p>
<p>The spike in activity among states seeking to break from these twice-yearly changes reflects how more people are recognizing the downsides of this practice. Now, it’s in the hands of legislators to decide whether to end the time shift altogether and to either choose a full year of having clocks more aligned with the sun or to artificially extend the day for more than half the year, for better or for worse.</p>
<p><em>This is an updated version of an article <a href="https://theconversation.com/why-daylight-saving-time-is-unhealthy-a-neurologist-explains-175427">originally published on March 10, 2022</a>.</em></p><img src="https://counter.theconversation.com/content/224597/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Beth Ann Malow is the Sleep Research Society representative to the Coalition for Permanent Standard TIme. </span></em></p>Americans have long been divided over adopting permanent standard versus permanent daylight saving time. But support for permanent standard time grew dramatically between 2021 and 2024.Beth Ann Malow, Professor of Neurology and Pediatrics, Vanderbilt UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1973432023-03-06T13:34:30Z2023-03-06T13:34:30ZSpringing forward into daylight saving time is a step back for health – a neurologist explains the medical evidence, and why this shift is worse than the fall time change<figure><img src="https://images.theconversation.com/files/512086/original/file-20230223-5904-84e4k9.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5621%2C3677&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Daylight saving time is back again – amid some controversy. </span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/illustration/spring-forward-royalty-free-illustration/900655094?phrase=Daylight%2BSavings%2BTime">billhagolan/iStock via Getty Images Plus</a></span></figcaption></figure><p>As people in the U.S. prepare to set their clocks ahead one hour on Sunday, March 12, 2023, I find myself bracing for the annual ritual of <a href="https://www.inquirer.com/news/standard-time-daylight-saving-time-clock-change-sleep-20201031.html">media stories</a> about <a href="https://qz.com/1114163/daylight-saving-time-dst-is-incredibly-disruptive-heres-how-to-reset/">the disruptions to daily routines</a> <a href="https://doi.org/10.5664/jcsm.8780">caused by switching from standard time </a> to daylight saving time. </p>
<p>About one-third of Americans say they don’t look forward to these twice-yearly time changes. And nearly two-thirds <a href="https://today.yougov.com/topics/politics/articles-reports/2021/11/04/daylight-saving-time-americans-want-stay-permanent">would like to eliminate them completely</a>, compared to 21% who aren’t sure and 16% who would like to keep moving their clocks back and forth. </p>
<p>But the effects go beyond simple inconvenience. Researchers are discovering that “springing ahead” each March is connected with serious negative health effects, including an uptick in <a href="https://doi.org/10.3390/jcm8030404">heart attacks</a> and <a href="https://doi.org/10.5664/jcsm.4938">teen sleep deprivation</a>. In contrast, the fall transition back to standard time is not associated with these health effects, as my co-authors and I noted in a <a href="https://doi.org/10.1001/jamaneurol.2019.3780">2020 commentary</a>.</p>
<p>I’ve studied the pros and cons of these twice-annual rituals for more than five years as a <a href="https://scholar.google.com/citations?user=ZddlKEoAAAAJ&hl=en">professor of neurology and pediatrics</a> and the director of Vanderbilt University Medical Center’s sleep division. It’s become clear to me and many of my colleagues that the transition to daylight saving time each spring affects health immediately after the clock change and also for the nearly eight months that <a href="https://www.cnn.com/2022/11/06/health/permanent-daylight-savings-health-harms-wellness/index.html#">Americans remain on daylight saving time</a>.</p>
<h2>The strong case for permanent standard time</h2>
<p>Americans are split on whether they <a href="https://today.yougov.com/topics/politics/articles-reports/2021/11/04/daylight-saving-time-americans-want-stay-permanent">prefer permanent daylight saving time</a> or <a href="https://apnorc.org/projects/dislike-for-changing-the-clocks-persists/">permanent standard time</a>. </p>
<p>However, the two time shifts – jolting as they may be – are not equal. Standard time most closely approximates natural light, with the sun directly overhead at or near noon. In contrast, during daylight saving time from March until November, the clock change resulting from daylight saving time causes natural light to be present one hour later in the morning and one hour later in the evening according to clock time.</p>
<p>Morning light is essential for helping to set the body’s natural rhythms: It <a href="https://doi.org/10.1038/s41598-018-36791-5">wakes us up and improves alertness</a>. Morning light also boosts mood – light boxes simulating natural light are prescribed for morning use <a href="https://doi.org/10.1001/archpsyc.55.10.890">to treat seasonal affective disorder</a>.</p>
<p>Although the exact reasons why light activates us and benefits our mood are not yet known, this may be due to light’s effects on <a href="https://doi.org/10.1080/10253890.2020.1741543">increasing levels of cortisol</a>, a hormone that <a href="https://doi.org/10.1038/s41574-019-0228-0">modulates the stress response</a> or the effect of <a href="https://doi.org/10.1038/s41598-018-36791-5">light on the amygdala</a>, a part of the brain involved in emotions.</p>
<p>Adolescents also may be <a href="https://theconversation.com/school-start-times-and-screen-time-late-in-the-evening-exacerbate-sleep-deprivation-in-us-teenagers-179178">chronically sleep deprived due to school</a>, sports and social activities. For instance, many <a href="https://nces.ed.gov/pubs2020/2020006/index.asp">children start school around 8 a.m.</a> or earlier. This means that during daylight saving time, many young people get up and travel to school in pitch darkness.</p>
<p>The body of evidence makes a good case for adopting permanent standard time nationwide, as I testified at a <a href="https://democrats-energycommerce.house.gov/committee-activity/hearings/rescheduled-hearing-on-changing-times-revisiting-spring-forward-fall">March 2022 Congressional hearing</a> and argued in a <a href="https://doi.org/10.1093/sleep/zsac236">recent position statement</a> for the Sleep Research Society. The American Medical Association recently <a href="https://www.ama-assn.org/press-center/press-releases/ama-calls-permanent-standard-time">called for permanent standard time</a>. And in late 2022, <a href="https://www.timeanddate.com/news/time/mexico-abolishes-dst-2022.html#">Mexico adopted permanent standard time,</a>, <a href="https://thehill.com/policy/international/3708301-mexicos-senate-votes-to-end-daylight-saving-time-for-most-of-the-country/">citing benefits to health, productivity and energy savings</a>. </p>
<figure class="align-center ">
<img alt="An illustration of two clocks depicting Daylight Savings Time changes: Fall backward, and spring forward." src="https://images.theconversation.com/files/446653/original/file-20220215-13-1d96ozk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/446653/original/file-20220215-13-1d96ozk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=360&fit=crop&dpr=1 600w, https://images.theconversation.com/files/446653/original/file-20220215-13-1d96ozk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=360&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/446653/original/file-20220215-13-1d96ozk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=360&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/446653/original/file-20220215-13-1d96ozk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=452&fit=crop&dpr=1 754w, https://images.theconversation.com/files/446653/original/file-20220215-13-1d96ozk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=452&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/446653/original/file-20220215-13-1d96ozk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=452&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">In 2023, clocks spring forward one hour at 2 a.m. on Sunday, March 12. They fall back at 2 a.m. on Sunday, Nov. 5.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/illustration/daylight-saving-time-fall-backward-and-royalty-free-illustration/1356689682?adppopup=true">iam2mai/iStock via Getty Images Plus</a></span>
</figcaption>
</figure>
<p>The biggest advantage of daylight saving time is that it provides an extra hour of light in the late afternoon or evening, depending on time of year, for sports, shopping or eating outside. However, exposure to light later into the evening for almost eight months during daylight saving time comes at a price. This extended evening light delays the brain’s release of melatonin, the hormone that promotes drowsiness, which in turn interferes with sleep and <a href="https://doi.org/10.1093/sleep/zsac236">causes us to sleep less overall</a>.</p>
<p>Because puberty also causes <a href="https://www.neurologylive.com/view/teenage-circadian-rhythm">melatonin to be released later at night</a>, meaning that teenagers have a delay in the natural signal that helps them fall asleep, adolescents are <a href="https://dx.doi.org/10.5664/jcsm.4938">particularly susceptible to sleep problems</a> from the extended evening light. This shift in melatonin during puberty lasts into our 20s.</p>
<h2>The ‘western edge’ effect</h2>
<p>Geography can also make a difference in how daylight saving time affects people. One study showed that people living on the western edge of a time zone, who get light later in the morning and later in the evening, <a href="https://doi.org/10.1016/j.jhealeco.2019.03.007">got less sleep</a> than their counterparts on the eastern edge of a time zone. </p>
<p>This study found that western-edge residents had higher rates of obesity, diabetes, heart disease and <a href="https://theconversation.com/breast-cancer-risk-higher-in-western-parts-of-time-zones-is-electric-light-to-blame-85803">breast cancer</a>, as well as lower per capita income and higher health care costs. Other research has found that <a href="https://doi.org/10.1158/1055-9965.EPI-16-1029">rates of certain other cancers are higher</a> on the western edge of a time zone. </p>
<p>Scientists believe that these health problems may result from a <a href="https://doi.org/10.3389/fphys.2019.00944">combination of chronic sleep deprivation and “circadian misalignment</a>.” Circadian misalignment refers to a mismatch in timing between our biological rhythms and the outside world. In other words, the timing of daily work, school or sleep routines is based on the clock, rather than on the sun’s rise and set. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/84aWtseb2-4?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">This video takes a deeper dive – all the way back to 1895 – into the history of daylight saving time.</span></figcaption>
</figure>
<h2>A brief history of daylight saving time</h2>
<p><a href="https://blogs.loc.gov/teachers/2017/03/world-war-i-and-daylight-savings-time/">Congress instituted year-round daylight saving time</a> during World War I and World War II, and <a href="https://www.mercurynews.com/2016/10/30/the-year-daylight-saving-time-went-too-far/">once again during the energy crisis</a> of the early 1970s.</p>
<p>The idea was that having extra light later into the afternoon would save energy by decreasing the need for electric lighting. This idea has since been <a href="https://doi.org/10.1016/j.jebo.2014.03.012">proved largely inaccurate</a>, as heating needs may increase in the morning in the winter, while air conditioning needs can also increase in the late afternoon in the summer.</p>
<p>Another pro-daylight saving argument has been that crime rates drop with <a href="https://doi.org/10.1162/REST_a_00547">more light at the end of the day</a>. While this has been proved true, the change is very small, and <a href="https://theconversation.com/is-daylight-saving-time-worth-the-trouble-research-says-no-86739">the health effects appear to outweigh</a> the benefits to society from lower rates of crime.</p>
<p>After World War II, designating the start and end dates for daylight saving time fell to state governments. Because this created many railroad scheduling and safety problems, however, Congress passed the <a href="https://www.transportation.gov/regulations/time-act#">Uniform Time Act in 1966</a>. This law set the nationwide dates of daylight saving time from the last Sunday in April until the last Sunday in October. In 2007, <a href="https://www.bts.gov/geospatial/daylight-savings-time">Congress amended the act</a> to expand the period in which daylight saving time is in effect from the second Sunday in March to the first Sunday in November – dates that remain in effect today.</p>
<p>The Uniform Time Act allows states and territories to opt out of daylight saving time, however. Arizona and Hawaii are on permanent standard time, along with Puerto Rico, the U.S. Virgin Islands, Northern Mariana Islands, Guam and American Samoa. </p>
<p>Now, many other states are considering whether to <a href="https://www.usatoday.com/story/news/nation/2021/11/04/daylight-saving-time-legislation-fall-back/6233980001/">stop falling back and springing ahead</a>. Several U.S. states have legislation and resolutions under consideration to support permanent standard time, while many others have been or are <a href="https://www.npr.org/2022/11/06/1134562545/daylight-saving-time-permanent-states">considering permanent daylight saving time</a>. Legislation and resolutions for permanent standard time have increased from 15% in 2021 to 31% in 2023. </p>
<p>In March 2022, the U.S. Senate <a href="https://www.congress.gov/bill/117th-congress/senate-bill/623">passed the Sunshine Protection Act </a> in a bid to <a href="https://www.reuters.com/world/us/us-senate-approves-bill-that-would-make-daylight-savings-time-permanent-2023-2022-03-15/">make daylight saving time permanent</a>. But the House did not move forward with this legislation. Florida Sen. Marco Rubio <a href="https://thehill.com/homenews/nexstar_media_wire/3880009-bill-to-make-daylight-saving-time-permanent-reintroduced-in-congress/">reintroduced the bill</a> on March 1, 2023. </p>
<p>The spike in activity among states seeking to break from these twice-yearly changes reflects how more people are recognizing the downsides of this practice. Now, it’s up to legislators to decide whether we end the time shift altogether, and to choose permanent standard or daylight saving time.</p>
<p><em>This is an updated version of an article <a href="https://theconversation.com/why-daylight-saving-time-is-unhealthy-a-neurologist-explains-175427">originally published on March 10, 2022</a>.</em></p><img src="https://counter.theconversation.com/content/197343/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Beth Ann Malow receives funding from the NIH as well as foundation funding, though none have been related to Daylight Saving Time.</span></em></p>Americans are divided on their preference for daylight saving time versus standard time. But research shows that our bodies fare better when aligned with the natural light of standard time.Beth Ann Malow, Professor of Neurology and Pediatrics, Vanderbilt UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1944172022-12-05T13:28:18Z2022-12-05T13:28:18ZShorter days affect the mood of millions of Americans – a nutritional neuroscientist offers tips on how to avoid the winter blues<figure><img src="https://images.theconversation.com/files/496594/original/file-20221121-18490-5tf8u2.jpg?ixlib=rb-1.1.0&rect=8%2C0%2C5742%2C3837&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">For those prone to seasonal affective disorder, a shift in the sleep cycle can impact energy levels.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/girl-alone-royalty-free-image/1129211268?phrase=seasonal%20affective%20disorder&adppopup=true">Ben Akiba/E+ via Getty Images</a></span></figcaption></figure><p>The annual pattern of winter depression and melancholy – better known as <a href="https://www.mayoclinic.org/diseases-conditions/seasonal-affective-disorder/symptoms-causes/syc-20364651">seasonal affective disorder, or SAD</a> – suggests a strong link between your mood and the amount of light you get during the day. </p>
<p>To put it simply: The less light exposure one has, the more one’s mood may decline.</p>
<p>Wintertime blues are common, but about 10 million Americans are affected every year by a longer lasting depression called <a href="https://www.bu.edu/articles/2019/seasonal-affective-disorder/">seasonal affective disorder</a>. Along with low mood, symptoms include anxious feelings, low self-esteem, longer sleep duration, constant craving for carbohydrates and low physical activity levels.</p>
<p><a href="https://www.binghamton.edu/decker/health-wellness-studies/profile.html?id=lina">I am a nutritional neuroscientist</a>, and my research focuses on the effects of diet and lifestyle factors on <a href="https://scholar.google.com/citations?user=sOMbzQ0AAAAJ&hl=en">mood and brain functions</a> such as mental distress, resilience and motivation. </p>
<p>Through my research, I have learned that seasonal affective disorder can strike anyone. However, people with a <a href="https://doi.org/10.1034/j.1600-0447.2000.101003176.x">history of mood disorders are at a higher risk</a>. In particular, young adults and women of all ages <a href="https://doi.org/10.1016/j.jadr.2021.100157">have an increased susceptibility</a>. </p>
<h2>Why seasonal depression happens</h2>
<p>When daylight saving time ends each fall, the one-hour shift backward reduces the amount of light exposure most people receive in a 24-hour cycle. As the days get shorter, people can experience general moodiness or a longer-term depression that is tied to a shorter exposure to daylight.</p>
<p>This happens due to a misalignment between the sleep-wake cycle, eating schedules and other daily tasks. Research shows that this mismatch may be associated <a href="https://doi.org/10.1038/s41398-020-0694-0">with poor mental health outcomes</a>, such as anxiety and depression. </p>
<p>Our sleep-wake cycle is controlled by the <a href="https://nigms.nih.gov/education/fact-sheets/Pages/circadian-rhythms.aspx">circadian rhythm</a>, an internal clock regulated by light and darkness. Like a regular clock, it <a href="https://theconversation.com/why-does-night-shift-increase-the-risk-of-cancer-diabetes-and-heart-disease-heres-what-we-know-so-far-190652">resets nearly every 24 hours </a> and controls metabolism, growth and hormone release. </p>
<p>When our brain receives signals of limited daylight, it <a href="https://www.nccih.nih.gov/health/melatonin-what-you-need-to-know">releases the hormone melatonin to support sleep</a> – even though we still have hours left before the typical bedtime. This can then affect how much energy we have, and when and how much we eat. It can also alter the brain’s ability to adapt to changes in environment. This process, called <a href="https://www.sciencedirect.com/topics/neuroscience/neuronal-plasticity">neuronal plasticity</a>, involves the growth and organization of neural networks. This is crucial for brain repair, maintenance and overall function.</p>
<p>It is possible to <a href="https://www.mayoclinic.org/diseases-conditions/seasonal-affective-disorder/diagnosis-treatment/drc-20364722">readjust the circadian rhythm</a> to better align with the new light and dark schedule. This means getting daylight exposure as soon as possible upon waking up, as well as maintaining sleep, exercise and eating routines that are more in sync with your routine prior to the time change. Eventually, people can gradually transition into the new schedule. </p>
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<figcaption><span class="caption">Sleeping too much or too little, bingeing on junk food and withdrawing from others are three symptoms of seasonal affective disorder.</span></figcaption>
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<h2>The intimate connection between serotonin and melatonin</h2>
<p>Serotonin is a chemical messenger in the brain that is a key player in regulating several functions such as <a href="https://my.clevelandclinic.org/health/articles/22572-serotonin#">mood, appetite and the circadian rhythm</a>. Serotonin also converts to melatonin with lower light intensity. As mentioned above, melatonin is a hormone that regulates the sleep-wake cycle and signals the brain that it’s time to sleep.</p>
<p>Less daylight exposure during winter months leads to the conversion of serotonin into melatonin <a href="https://doi.org/10.1126/science.7434030">earlier in the evening</a>, since it gets dark earlier. As a result, this untimely melatonin release causes a disruption in the sleep-wake cycle. For some people this can cause moodiness, daytime sleepiness and loss of appetite regulation, typically leading to unhealthy snacking. People with seasonal affective disorder often <a href="https://doi.org/10.1016/S0149-7634(02)00004-0">crave foods rich in simple sugars, such as sweets</a>, because there is an intimate connection between <a href="https://doi.org/10.1093/cdn/nzab049_009">carbohydrate consumption, appetite regulation and sleep</a>. </p>
<h2>Strategies to combat the winter blues</h2>
<p>In winter, most people leave work when it’s turning dark. For this reason, <a href="https://www.mayoclinic.org/diseases-conditions/seasonal-affective-disorder/in-depth/seasonal-affective-disorder-treatment/art-20048298">light therapy is typically recommended</a> for those who experience seasonal affective disorder, or even shorter periods of seasonal funk. </p>
<p>This can be as simple as getting some light shortly after awakening. Try to get at least one hour of natural light during the early morning hours, preferably about <a href="https://www.cdc.gov/niosh/emres/longhourstraining/light.html#:%7E:">one hour after your usual morning wake-up time</a> when the circadian clock is most sensitive to light. This is true no matter what your wake-up time is, as long as it’s morning. For people living at northern latitudes where there’s very little sun in winter, light therapy boxes – <a href="https://www.mayoclinic.org/diseases-conditions/seasonal-affective-disorder/in-depth/seasonal-affective-disorder-treatment/art-20048298">which replicate outdoor light</a> – can be effective. </p>
<p>You can also improve your sleep quality by avoiding stimulants like coffee, tea or heavy meals close to bedtime. <a href="https://doi.org/10.1113/JP276943">Exercising during the day is also good</a> – it increases serotonin production and supports circadian regulation. A balanced diet of complex carbs and healthy proteins <a href="https://doi.org/10.1016/j.jand.2022.01.007">supports steady serotonin and melatonin production</a>, and practicing downtime before bed can reduce stress. </p>
<p>Taking these small steps may help the circadian rhythm adjust faster. For the millions with mood disorders, that could mean happier times during what are literally the darkest days.</p><img src="https://counter.theconversation.com/content/194417/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Lina Begdache does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Research shows that young adults and women are particularly susceptible to seasonal affective disorder.Lina Begdache, Associate Professor of Health and Wellness Studies, Binghamton University, State University of New YorkLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1791782022-09-16T12:18:30Z2022-09-16T12:18:30ZSchool start times and screen time late in the evening exacerbate sleep deprivation in US teenagers<figure><img src="https://images.theconversation.com/files/480610/original/file-20220823-14-84rrxh.jpg?ixlib=rb-1.1.0&rect=9%2C9%2C5997%2C3998&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Less than 30% of teenagers are getting the sleep they need.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/portrait-of-teenage-boy-in-the-library-royalty-free-image/1155169520?adppopup=true">Mayur Kakade/Moment via Getty Images</a></span></figcaption></figure><p>With the school year underway around the U.S., parents and caregivers are once again faced with the age-old struggle of wrangling groggy kids out of bed in the morning. For parents of preteens and teenagers, it can be particularly challenging.</p>
<p>Sometimes this gets chalked up to laziness in teens. But the main reason why a healthy person is unable to naturally wake up without an alarm is that they are not getting the sleep their brain and body need. </p>
<p>That’s because studies show that <a href="https://doi.org/10.1093/sleep/zsy011">adolescents need more than nine hours of daily sleep</a> to be physically and mentally healthy. </p>
<p>But the likelihood that you know a teenager who gets enough sleep is rather slim. In the U.S., <a href="https://www.cdc.gov/mmwr/volumes/67/wr/mm6703a1.htm?s_cid=mm6703a1_w">less than 30% of high school students</a> – or those in grades 9 through 12 – sleep the recommended amount, according to the Centers for Disease Control and Prevention. Among middle schoolers in grades 6-8, nearly 60% do not get enough sleep at night. </p>
<p>Yet my laboratory’s research suggests that a much higher percentage of teens are getting too little sleep.</p>
<p>I am a <a href="https://www.biology.washington.edu/people/profile/horacio-de-la-iglesia">professor of biology</a> and have been <a href="https://scholar.google.com/citations?user=I-8qCAYAAAAJ&hl=en">studying sleep and circadian rhythms for more than 30 years</a>. For the past seven years, my laboratory at the University of Washington has been doing research on sleep in Seattle-area teenagers. Our research has found that, just as in other areas of the U.S., <a href="https://doi.org/10.1126/sciadv.aau6200">high schoolers</a> in Seattle are not getting the amount of sleep they need. Our study objectively measured sleep in 182 high school sophomores and seniors and found only two that slept at least nine hours at night during school days. </p>
<p>Our studies and those of others indicate that three important factors lie behind this lack-of-sleep epidemic: a physiological regulation of sleep that leads to a delayed sleep timing in teens and that is not aligned with early <a href="https://doi.org/10.1177%2F0748730419892118">school start times</a>, a <a href="https://doi.org/10.1177%2F0748730419892111">lack of morning exposure to daylight</a> and <a href="https://doi.org/10.1177%2F0748730419892111">excessive exposure to bright electric light and screens</a> late in the evening. </p>
<h2>Teen sleep biology</h2>
<p>The time people go to bed, fall asleep and wake up is governed by <a href="https://doi.org/10.1111/jsr.12371">two main factors in the brain</a>. The first is a so-called “wakefulness tracker,” a physiological timer that increases our need to sleep the longer we stay awake. This is in part the consequence of the accumulation of chemical signals released by neurons, <a href="https://doi.org/10.1111/jsr.13597">such as adenosine</a>.</p>
<p>Adenosine accumulates in the brain when we are awake, leading to increased sleepiness as the day wears on. If, for instance, a person wakes up at 7 a.m., these chemical signals will accumulate throughout the day until the levels are high enough that the person will fall asleep, typically in the late evening.</p>
<p>The second factor that drives the sleep/wake cycle is a 24-hour biological clock that tells our brain what times of the day we should be awake and what times we should be sleeping. <a href="https://theconversation.com/your-body-has-an-internal-clock-that-dictates-when-you-eat-sleep-and-might-have-a-heart-attack-all-based-on-time-of-day-178601">This biological clock </a> is located in an area of the brain called the hypothalamus. The clock is composed of neurons that coordinate the brain areas regulating sleep and wakefulness to a 24-hour sleep/wake cycle.</p>
<p>These two regulators operate with relative independence from each other. But under typical conditions, they are coordinated so that a person with access to electric-powered light would fall asleep in the late evening – between about 10 p.m. to 11 p.m., and wake up in the early morning, around 6 a.m. to 7 a.m. </p>
<p>So why do teenagers often want to go to bed later and wake up later than their parents? </p>
<p>It turns out that during adolescence, both the wakefulness tracker and the biological clock conspire to delay the timing of sleep. First, adolescents can be awake until later hours before their wakefulness tracker <a href="https://doi.org/10.1093/sleep/28.11.1446">makes them feel sleepy enough to fall sleep</a>.</p>
<p>Second, the <a href="https://doi.org/10.1016/j.adolescence.2018.06.001">biological clock of teenagers is delayed</a> because in some cases it appears to run at a slower pace, and because it responds differently to light cues that reset the clock daily. This combination leads to a sleep cycle that operates a couple of hours later than in an older adult – if an older adult feels the signals to fall asleep around 10 p.m. or 11 p.m., this won’t happen until midnight or later in a teenager. </p>
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<figcaption><span class="caption">Sufficient sleep is key to teen health, but many things prevent adolescents from getting enough of it.</span></figcaption>
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<h2>How school start times contribute</h2>
<p>To help find more hours of sleep for teens, one measure that some <a href="https://www.theatlantic.com/family/archive/2022/06/american-high-school-later-start-time/661211/">school districts around the country have taken</a> is to delay the school start time for middle schools and high schools. The American Academy of Pediatrics recommends that <a href="https://doi.org/10.1542/peds.2014-1697">schools for this age group should not start before 8:30 a.m.</a>. Yet the majority of <a href="https://nces.ed.gov/pubs2020/2020006/index.asp">high schools in the U.S start at 8 a.m. or earlier</a>.</p>
<p>Based on the recommendation of sleep experts, the Seattle school district, beginning with the 2016-2017 school year, delayed middle school and high school start times by nearly an hour, from 7:50 a.m. to 8:45 a.m. In a study our team conducted after the district enacted the plan, we found that <a href="https://doi.org/10.1126/sciadv.aau6200">students gained 34 minutes of daily sleep</a> – a huge gain by sleep medicine standards. In addition, student attendance and punctuality improved, and median grades went up by 4.5%. </p>
<p>Despite an abundance of research evidence and the advice from virtually all sleep experts in the country, most school districts are still stuck with school start times that promote chronic sleep deprivation in teenagers. The early school starts are further <a href="https://doi.org/10.1177%2F0748730419854197">aggravated by daylight saving time</a> – when clocks are set one hour ahead in the springtime. This time shift – one that <a href="https://www.nbcchicago.com/news/local/permanent-daylight-saving-time-up-in-the-air-as-house-mulls-when-to-consider-bill-2/2934856/">could become permanent in the U.S. in 2023</a> – exposes teenagers to artificially dark mornings, which exacerbates <a href="https://theconversation.com/why-daylight-saving-time-is-unhealthy-a-neurologist-explains-175427">their naturally delayed sleep timing</a>. </p>
<h2>Teaching healthy sleep habits to teens</h2>
<p>School start times aside, kids also need to learn the importance of healthy habits that promote sufficient sleep. </p>
<p>Getting bright daylight exposure, particularly during the morning, pushes our biological clock to an earlier time. This, in turn, will promote an earlier bedtime and a natural early morning wake time. </p>
<p>In contrast, light in the evening – including the light emitted by screens – is highly stimulating to the brain. It inhibits the production of natural signals such as melatonin, a hormone that is produced by the brain’s pineal gland <a href="https://www.nccih.nih.gov/health/melatonin-what-you-need-to-know">as the night arrives and in response to darkness</a>. But when these cues are inhibited by artificial light in the evening, our biological clocks are delayed, promoting a later bedtime and a later morning wake time. And thus the cycle of having to roust a sleepy, yawning teenager from bed for school begins again.</p>
<p>Yet few schools teach the importance of good daily routines and sleep timing, and parents and teens also do not fully appreciate their importance. <a href="https://www.penguinrandomhouse.com/books/647334/generation-sleepless-by-heather-turgeon-mft-and-julie-wright-mft-foreword-by-daniel-j-siegel/">Chronic sleep deprivation</a> disrupts every physiological process in the body and has been consistently linked to disease, including <a href="https://doi.org/10.1016/j.cpr.2018.05.006">depression and anxiety</a>, <a href="https://doi.org/10.1111/jsr.13162">obesity</a> and <a href="https://doi.org/10.1016/j.neubiorev.2022.104832">addictive behavior</a>. </p>
<p>Conversely, sufficient sleep not only helps to reduce <a href="https://doi.org/10.1146/annurev-psych-010213-115205">physical</a> ailments and improve <a href="https://doi.org/10.1038/s44159-022-00074-8">mental health</a>, but it has also been shown to be <a href="https://www.ted.com/talks/valerie_crabtree_teen_sleep_what_is_it_good_for_absolutely_everything?utm_campaign=tedspread&utm_medium=referral&utm_source=tedcomshare">fundamental for optimal physical and mental performance</a>.</p><img src="https://counter.theconversation.com/content/179178/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Horacio de la Iglesia receives funding from NIH.</span></em></p>Adolescent biology, early morning classes and too much evening screen time are a few of the key drivers behind teen sleep deprivation.Horacio de la Iglesia, Professor of Biology, University of WashingtonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1797392022-04-05T19:01:34Z2022-04-05T19:01:34Z5 ways Americans’ lives will change if Congress makes daylight saving time permanent<figure><img src="https://images.theconversation.com/files/455408/original/file-20220331-23-b8vw9u.jpg?ixlib=rb-1.1.0&rect=12%2C0%2C4288%2C2869&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Some people dread the time change that occurs twice a year -- and for good reason.</span> <span class="attribution"><a class="source" href="https://mapi.associatedpress.com/v1/items/8514f28d62a24644a197457ff476158d/preview/AP21069720554516.jpg?wm=api&tag=app_id=1,user_id=849163,org_id=101781">AP Photo/Elise Amendola</a></span></figcaption></figure><p>The U.S. <a href="https://thehill.com/homenews/house/598827-daylight-savings-change-faces-trouble-in-house">Senate approved</a> the Sunshine Protection Act in March 2022, with the goal of making daylight saving time permanent starting in November 2023. If that happens, the U.S. will never again “spring forward” or “fall back.”</p>
<p>Following the Senate’s vote and a recent hearing in the <a href="https://energycommerce.house.gov/committee-activity/hearings/rescheduled-hearing-on-changing-times-revisiting-spring-forward-fall">House Subcommittee on Consumer Protection and Commerce</a> – at which I testified – the subcommittee is now considering the issue. The full House of Representatives will need to vote in support of permanent DST before the bill goes to President Biden’s desk for his signature.</p>
<p>In <a href="https://digitalcommons.law.uw.edu/faculty-articles/134/">my research</a> on DST, <a href="https://www.law.uw.edu/directory/faculty/calandrillo-steve">I have found</a> that Americans don’t like Congress messing with their clocks. However, the move to DST year-round makes a lot of sense.</p>
<p>In an effort to avoid the biannual time change in spring and fall, some DST critics have suggested that returning to permanent standard time <a href="https://theconversation.com/why-daylight-saving-time-is-unhealthy-a-neurologist-explains-175427">would benefit society</a>. </p>
<p>But research shows that DST <a href="https://digitalcommons.law.uw.edu/faculty-articles/134/">saves lives and prevents crime</a>. <a href="https://www.usatoday.com/story/news/nation/2021/11/04/daylight-saving-time-legislation-fall-back/6233980001/">Nearly 20 states</a> have passed bills to make DST permanent, and the Senate unanimously passed the Sunshine Protection Act to allow those laws to take effect – since any one state <a href="https://www.transportation.gov/regulations/time-act#:%7E:text=Today%2C%20the%20Uniform%20Time%20Act,change%20a%20time%2Dzone%20boundary.">can’t move to DST unilaterally</a> on dates different from the rest of the country.</p>
<p>If Congress ultimately passes the measure to turn all clocks forward permanently, I see five ways that Americans’ lives will improve.</p>
<h2>1. Lives would be saved</h2>
<p>Simply put, darkness kills – and darkness in the evening is far deadlier than darkness in the morning. </p>
<p>The evening rush hour is twice as fatal as the morning for various reasons. <a href="https://dx.doi.org/10.1136%2Fip.2005.011056">Far more people are on the road</a>, more alcohol is in drivers’ bloodstreams, people are hurrying to get home and more children are enjoying <a href="http://commdocs.house.gov/committees/science/hsy73325.000/hsy73325_0.HTM">outdoor, unsupervised play</a>. Fatal vehicle-on-pedestrian crashes <a href="https://doi.org/10.2105/ajph.85.1.92">increase threefold</a> when the sun goes down.</p>
<p>DST brings an extra hour of sunlight into the evening to mitigate those risks. Standard time has the opposite impact, by moving sunlight to the morning. </p>
<p>A metastudy reviewing all of the available research on the topic demonstrated that <a href="https://doi.org/10.1016/S0001-4575(03)00015-0">343 lives per year</a> could be saved by moving to year-round DST, primarily in reduced vehicle on pedestrian accidents. Mornings would be riskier, but afternoons/evenings would be far more safe. </p>
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<h2>2. Crime would decrease</h2>
<p>Darkness is also a friend of crime. Moving sunlight into the evening has a far greater impact on crime prevention than it does in the morning. This is especially true for <a href="https://www.ojjdp.gov/ojstatbb/offenders/qa03401.asp?qaDate=2016">crimes by juveniles</a>, which peak in the after-school and early evening hours.</p>
<p>Criminals prefer to do their work in the darkness of evening and night. <a href="https://doi.org/10.1016/S0169-2070(03)00093-1">Crime rates are 30% lower</a> in the morning hours, even when those morning hours occur before sunrise, when it’s still dark.</p>
<p>A 2013 British study found that improved lighting in the evening hours could <a href="https://doi.org/10.4073/csr.2008.13">reduce the crime rate by up to 20%</a>. </p>
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<h2>3. Energy would be saved</h2>
<p>Many people don’t know that the <a href="https://digitalcommons.law.uw.edu/faculty-articles/134/">original justification for the creation of DST</a> was to save energy – initially during World War I and II to prioritize energy for U.S. troops, and then later during the 1973 OPEC oil crisis. When the sun is out later in the evening, peak energy loads are reduced.</p>
<p>Having more sun in the evening requires not just less electricity to provide lighting, but <a href="https://www1.eere.energy.gov/ba/pba/pdfs/edst_national_energy_consumption.pdf">reduces the amount of oil and gas</a> required to heat homes and businesses, though it could increase cooling costs in the summer. DST resulted in <a href="https://www.presidency.ucsb.edu/documents/statement-signing-the-emergency-daylight-saving-time-energy-conservation-act-1973">150,000 barrels of oil saved</a> by the U.S. in 1973, which helped combat the effect of OPEC’s oil embargo.</p>
<p>Most people in our society are awake and using energy in the early evening when the sun sets. But a considerable portion of the population is still asleep at sunrise, resulting in significantly less demand for energy then.</p>
<p>This rationale motivated some in California to <a href="https://digitalcommons.law.uw.edu/faculty-articles/134/">recommend permanent DST in the early 2000s</a>, when the state experienced recurrent electricity shortages and rolling brownouts. The American Council for an Energy-Efficient Economy estimated that the U.S. would have seen an <a href="https://thehill.com/blogs/congress-blog/politics/597190-to-jumpstart-the-economy-make-daylight-saving-time-permanent/">energy savings of more than US$4 billion</a> and a decrease of carbon emissions by 10.8 million metric tons if we had enacted permanent DST more than decade ago.</p>
<h2>4. Avoiding clock switches improves sleep</h2>
<p>Critics of DST are correct about one thing: The biannual clock switch is bad for health and welfare.</p>
<p>It wreaks havoc with people’s sleep cycles. Heart attacks <a href="https://healthblog.uofmhealth.org/heart-health/why-daylight-saving-time-could-increase-your-heart-attack-risk">increase 24%</a> in the week after the U.S. “springs forward” in March. There’s even an uptick during the week when clocks “fall back.” </p>
<p>If that’s not bad enough, a study from 2000 shows that major financial market indexes NYSE, AMEX and NASDAQ <a href="https://www.jstor.org/stable/117321?seq=1#metadata_info_tab_contents">average negative returns</a> on the Monday following both clock switches, presumably because of disrupted sleep cycles.</p>
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<p>Critics of biannual clock switching sometimes use these points to argue in favor of permanent standard time. However, the same sleep benefits are available under year-round DST, too. Plus, standard time doesn’t offer the energy-saving, lifesaving or crime prevention effects of DST.</p>
<h2>5. Recreation and commerce flourish in the sun</h2>
<p>Recreation and commerce flourish in daylight and are hampered by evening darkness.</p>
<p>Americans are <a href="https://qz.com/1120488/daylight-saving-time-as-americans-know-it-was-instituted-by-corporate-lobbies-not-farmers/">less willing to go out to shop in the dark</a>, and it’s not very easy to catch a baseball in darkness either. These activities are far more prevalent in the early evening than they are in the early morning hours, so sunlight is not nearly so helpful then.</p>
<p>Not surprisingly, the U.S. Chamber of Commerce and organizations devoted to outdoor recreation <a href="https://www.washingtonpost.com/opinions/five-myths-about-daylight-saving-time/2015/03/06/970092d4-c2c1-11e4-9271-610273846239_story.html?utm_term=.d446e4c4cf34">favor extended DST</a>. Brick-and-mortar stores, especially family-owned businesses, suffered during the pandemic. <a href="https://thehill.com/blogs/congress-blog/politics/597190-to-jumpstart-the-economy-make-daylight-saving-time-permanent/">Having more daylight to shop</a> helps to reverse the trend.</p>
<h2>A note about the downsides of DST</h2>
<p>It is important to note that some research highlights the downsides of DST.</p>
<p>The first concern is that <a href="https://doi.org/10.5664/jcsm.4938">DST creates sleep disruptions</a>. </p>
<p>But most circadian rhythm dysfunction is created by the <a href="https://doi.org/10.1371/journal.pcbi.1007927">biannual clock shift itself</a>. Either permanent standard time or permanent DST solves that problem. Standard time may be <a href="https://doi.org/10.1001/jamaneurol.2019.3780">better for circadian rhythms</a> overall because the sun sets and rises earlier; however, people’s evening activities and routines are unlikely to change in response. Earlier sunsets won’t force people to go to bed earlier, as might have been the case 150 years ago before electricity. “Prime time” is <a href="https://www.marketingcharts.com/television-28359">8 to 11 p.m.</a>, not 5 to 6 a.m., for a reason.</p>
<p>Other research has <a href="https://doi.org/10.1158/1055-9965.EPI-16-1029">associated living in western portions of time zones</a> – which have longer evening sun – <a href="https://www.livescience.com/58504-how-time-zones-may-affect-cancer-risk.html">with an increased cancer risk</a> compared with those living in eastern portions. The increased cancer risk may be partially explained by lifestyle choices, like diet and exercise, in different parts of time zones.</p>
<p>Further, Americans make decisions all the time that we know have health risks, like eating red meat instead of broccoli and drinking alcohol or soda instead of water. We do this because we enjoy the benefits of those products despite their risks. This is similar to sun exposure and later bedtimes; we enjoy and benefit from them even though we know they carry risks.</p>
<p>[<em>Over 150,000 readers rely on The Conversation’s newsletters to understand the world.</em> <a href="https://memberservices.theconversation.com/newsletters/?source=inline-150ksignup">Sign up today</a>.]</p>
<p>To address another downside – early morning winter darkness – any switch to permanent DST could be coupled with efforts to move school start times later, as long advocated by the <a href="https://doi.org/10.1542/peds.2014-1697">American Academy of Pediatrics</a>. This would be a good idea for kids’ <a href="https://doi.org/10.1542/peds.2014-1697">circadian rhythms and mental health</a>, regardless of DST or standard time. Stepped-up child safety measures for darker mornings, such as crosswalk lighting and more crossing guards, would also help. </p>
<p>Time will tell whether the U.S. adopts permanent DST, but either way, we should consider all of its benefits versus all of the costs.</p>
<p><em>This is an updated version of a <a href="https://theconversation.com/5-ways-life-would-be-better-if-it-were-always-daylight-saving-time-111506">story that was originally published</a> on March 4, 2019, and updated on March 3, 2020.</em></p><img src="https://counter.theconversation.com/content/179739/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Steve Calandrillo does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Research suggests that permanent daylight saving time would save lives as well as energy and prevent crime.Steve Calandrillo, Professor of Law, University of WashingtonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1800632022-03-28T13:20:43Z2022-03-28T13:20:43ZDaylight savings: how an hour of extra sunlight can benefit your mental health<figure><img src="https://images.theconversation.com/files/454656/original/file-20220328-27-15lwr3i.jpg?ixlib=rb-1.1.0&rect=26%2C0%2C3000%2C1998&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/man-walking-dog-early-morning-by-562654981">Boris Medvedev/Shutterstock</a></span></figcaption></figure><p>In many northern hemisphere countries, people have now adjusted the clock one hour forwards and are enjoying an extra hour of daylight in the evenings. As the weather becomes a little warmer, too, this gives us that pleasant feeling that summer isn’t too far away.</p>
<p>But there are a variety of ways extra daylight can improve our wellbeing.</p>
<p>When sunlight hits a specific area of the retina in your eyes, this actually triggers the release of <a href="https://faseb.onlinelibrary.wiley.com/doi/full/10.1096/fj.14-268342">serotonin</a> (the “feel-good” chemical) in the brain. An increase in serotonin is linked to <a href="https://www.hra.nhs.uk/planning-and-improving-research/application-summaries/research-summaries/serotonin-emotion-and-behaviour/">higher mood</a> levels.</p>
<p>In fact, a lack of sunlight can lead to a condition called <a href="https://theconversation.com/seasonal-depression-why-it-happens-and-how-to-manage-the-symptoms-171257">seasonal affective disorder</a> (SAD), sometimes called “winter depression”. This disorder, characterised by low mood, is most common during the winter months when there are fewer hours of daylight. </p>
<p>The sun is a source of vitamin D, which has some important functions in the body, such as <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4070857/">reducing inflammation</a>. Aside from its physical health benefits, a <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2908269/">lack of vitamin D</a> can cause people to feel low and anxious, while exposure to direct sunlight can improve mood. Just five to 15 minutes in the sun is enough to reap the benefits associated with vitamin D. </p>
<p>Sunlight also supports the <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2290997/">production of melatonin</a>, the chemical that helps us to <a href="https://pubmed.ncbi.nlm.nih.gov/32156230/#:%7E:text=Results%3A%20Vitamin%20D%20receptors%20and,human%20circadian%20rhythms%20and%20sleep">sleep well</a> – insomnia is more common during the darker winter months. And getting a good night’s sleep has <a href="https://www.nhs.uk/live-well/sleep-and-tiredness/why-lack-of-sleep-is-bad-for-your-health/">a positive effect</a> on our wellbeing.</p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/seasonal-depression-why-it-happens-and-how-to-manage-the-symptoms-171257">Seasonal depression: why it happens – and how to manage the symptoms</a>
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<p>More hours of daylight can also encourage people to socialise more. Socialising and connecting with other people is associated with <a href="https://journals.sagepub.com/doi/full/10.1177/000486741772399">improved mood and wellbeing</a>. </p>
<p>More light in the evenings also gives many people more of an opportunity to go outside at the end of the day. While the physical and mental health benefits of doing exercise are well known, simply being <a href="http://www.awp.nhs.uk/news-publications/trust-news/2021/may/embracing-the-power-of-nature-to-boost-mental-health/">outdoors in nature</a> can improve our wellbeing. It can have a calming effect on the mind and can create a feeling of peace. It can also help us to cope with everyday stresses and mental fatigue.</p>
<p>The therapeutic benefit of being outside in nature is such that “nature therapy”, “<a href="https://www.frontiersin.org/articles/10.3389/fpsyg.2018.01389/full">ecotherapy</a>” or “green therapy” are often recommended as part of treatment for conditions such as depression.</p>
<figure class="align-center ">
<img alt="A group of people socialising outdoors." src="https://images.theconversation.com/files/454675/original/file-20220328-21-sc6519.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/454675/original/file-20220328-21-sc6519.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/454675/original/file-20220328-21-sc6519.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/454675/original/file-20220328-21-sc6519.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/454675/original/file-20220328-21-sc6519.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/454675/original/file-20220328-21-sc6519.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/454675/original/file-20220328-21-sc6519.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">We might socialise more when the days are longer.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/six-adult-friends-enjoying-party-on-785101684">Monkey Business Images/Shutterstock</a></span>
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</figure>
<p>With all this in mind, it’s perhaps not surprising that evidence shows that when the clocks go back in the autumn the rate of mental and emotional problems <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7302868/">increases</a> compared to when the clocks go forwards in spring. </p>
<h2>Making the most of it</h2>
<p>After two years of the COVID pandemic, and as the war continues to rage in Ukraine, taken with the worries of everyday life, it’s natural to be feeling stressed and emotionally fatigued. Making the most of the extra daylight is a small thing you can do which might boost your mood. </p>
<p>Simply going out into your garden to enjoy the longer hours of daylight can be revitalising. If you don’t have a garden – or even if you do – make the most of outdoor spaces such as parks.</p>
<p>You could also try mindfulness meditation. This involves sensing what’s happening around you in the moment (such as the noises and the smells) and allowing yourself to think up positive imagery (such as lying on a sandy beach with the waves crashing in the distance) without judging or interpreting what you are thinking about. Sometimes referred to as “<a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6176042/">guided imagery</a>”, practising this can help you to relax both your body and mind, which can in turn reduce feelings of stress and anxiety.</p>
<p>Being in and around nature can enhance this process, allowing you to pay attention to the sounds of birds, the smells of flowers, the warm sensation of the sun on your skin. Find somewhere peaceful to sit quietly, and focus on taking slow breaths. As with any new skill, this needs to be built up incrementally. Start with five minutes, and with regular practice, you’ll soon be able to do it for much longer.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/why-the-clocks-changing-are-great-for-your-brain-86003">Why the clocks changing are great for your brain</a>
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</em>
</p>
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<p>The extra hour of light at the end of the day should be even more meaningful to us because of all the extra time over the past two years we’ve spent stuck indoors. So use this valuable daylight – get away from your desk, take a walk, and pay attention to what’s around you. There’s a good chance you’ll feel better for it.</p><img src="https://counter.theconversation.com/content/180063/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>From boosted mood, to improved sleep, to more impetus to be outdoors and socialise, longer daylight can have a variety of direct and indirect benefits on our wellbeing.Anne Fothergill, Principal Lecturer, Mental Health, University of South WalesShaun Hough, Senior Lecturer, Mental Health, University of South WalesLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1791542022-03-11T20:28:15Z2022-03-11T20:28:15Z11 things you can do to adjust to losing that hour of sleep when daylight saving time starts<figure><img src="https://images.theconversation.com/files/451655/original/file-20220311-17-3bxspk.jpg?ixlib=rb-1.1.0&rect=826%2C135%2C4473%2C3035&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The time change can make you feel jet-lagged.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/tired-toddler-girl-sitting-at-table-royalty-free-image/149411429">Laura Olivas/Moment via Getty Images</a></span></figcaption></figure><p>As clocks march ahead and daylight saving time begins, there can be anxiety around losing an hour of sleep and how to adjust to this change.</p>
<p>Usually an hour seems like an insignificant amount of time, but even this <a href="https://doi.org/10.1016/j.ejim.2019.01.001">minimal loss can cause problems</a>. There can be <a href="https://doi.org/10.1371/journal.pcbi.1007927">significant health repercussions</a> of this forcible shift in the body clock. </p>
<p>Springing forward is usually harder that falling backward. Why?</p>
<p>The natural internal body clock rhythm in people tends to be <a href="https://www.cdc.gov/niosh/emres/longhourstraining/clock.html">slightly longer than 24 hours</a>, which means that every day we tend to delay our sleep schedules. Thus, “springing forward” goes against the body’s natural rhythm. It is similar to a mild case of jet lag caused by traveling east – in which you lose time and have trouble falling asleep at an earlier hour that night.</p>
<p>Even though it’s technically just one hour lost due to the time change, the amount of sleep deprivation due to disrupted sleep rhythm lasts for many days and often throws people off schedule, leading to cumulative sleep loss.</p>
<p><a href="https://www.pediatrics.pitt.edu/people/deepa-burman-md-faasm">We</a> <a href="https://www.pediatrics.pitt.edu/people/hiren-muzumdar-md">lead</a> a sleep evaluation center at the University of Pittsburgh Medical Center Children’s Hospital of Pittsburgh and regularly see <a href="https://doi.org/10.3390/healthcare7010001">patients who are dealing with sleep loss</a> and internal clocks that are not synchronized with external time. Our experience has shown us that it’s important to prepare, as much as possible, for the time shift that occurs every spring.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/262540/original/file-20190306-100805-1rcfigv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="woman at laptop yawns and rubs face" src="https://images.theconversation.com/files/262540/original/file-20190306-100805-1rcfigv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/262540/original/file-20190306-100805-1rcfigv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/262540/original/file-20190306-100805-1rcfigv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/262540/original/file-20190306-100805-1rcfigv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/262540/original/file-20190306-100805-1rcfigv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=504&fit=crop&dpr=1 754w, https://images.theconversation.com/files/262540/original/file-20190306-100805-1rcfigv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=504&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/262540/original/file-20190306-100805-1rcfigv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=504&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Sleep loss from springing forward has been associated with not only sleepiness at work but also an increase in work accidents.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/portrait-young-woman-sitting-table-front-472129438">fizkes/Shutterstock.com</a></span>
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<h2>Consequences of sleep loss vary</h2>
<p>Many studies have demonstrated that there is an increased risk of <a href="https://doi.org/10.1016/j.sleep.2020.07.048">heart attack, stroke and high blood pressure</a> associated with sleep deprivation. <a href="https://www.ncbi.nlm.nih.gov/books/NBK19958/">Workplace injuries</a> increase and so do <a href="https://doi.org/10.1093/sleep/zsy144">automobile accidents</a>. Adolescents often find it harder to wake up in time to get to school and may have difficulties with <a href="https://doi.org/10.5664/jcsm.4938">attention and school performance</a> or <a href="https://doi.org/10.1016/S1389-9457(03)00101-1">worsening of mental health problems</a>.</p>
<p>Is there something to be done to help to deal with this loss of sleep and change of body clock timing?</p>
<p>Of course. The first step is increasing awareness and using the power of knowledge to combat this issue. Here are some quick tips to prepare yourself for the upcoming weekend.</p>
<ol>
<li><p>Do not start with a “sleep debt.” Ensure that you and, if you’re a parent, your child get adequate sleep on a regular basis leading up to the time change each year. Most adults need anywhere from <a href="https://doi.org/10.1016/j.sleh.2014.12.010">seven to nine hours of sleep</a> daily to perform adequately. Children have <a href="https://www.aap.org/en-us/about-the-aap/aap-press-room/pages/American-Academy-of-Pediatrics-Supports-Childhood-Sleep-Guidelines.aspx">varying requirements for sleep</a> depending on their age.</p></li>
<li><p>Prepare for the time change. Going to bed – and for parents, putting your kids to bed – 15 to 20 minutes earlier each night in the week preceding the time change is ideal. Having an earlier wake time can help you get to sleep earlier. Try to wake up an hour earlier than is customary on Saturday, the day before the time change. If you have not been able to make any changes to your sleep schedule in advance, then keep a very consistent wake time on weekdays as well as weekends to adjust to the time change more easily. </p></li>
<li><p>Use light to your advantage. <a href="https://doi.org/10.1113/JP275501">Light is the strongest cue</a> for adjusting the internal body clock. Expose yourself to bright light upon waking as you start getting up earlier in the week before daylight saving time. If you live in a place where natural light is limited in the morning after clocks change, use bright artificial light to signal your body clock to wake up earlier. As the season progresses, this will be less of an issue as the sun rises earlier in the day.</p></li>
<li><p>At night, minimize exposure to bright light and especially the blue light emitted by the screens of electronic media. This light can <a href="https://doi.org/10.1016/j.sleep.2021.05.046">shift your body rhythm</a> and signal your internal clock to wake up later the next day. If your devices permit, set their screens to dim and emit less blue light in the evening.</p></li>
<li><p>In some geographic locations, it might be helpful to have room-darkening curtains at bedtime depending on how much sunlight your room gets at bedtime. Be sure to open the curtains in the morning to allow the <a href="https://doi.org/10.1016/j.sleep.2006.11.008">natural morning light</a> to set your sleep-wake cycle.</p></li>
<li><p>Carefully plan your day and evening activities. The night before the time change, set yourself up for a good night’s sleep by incorporating relaxing activities that can help you wind down, such as reading a book or meditating.</p></li>
<li><p>Incorporate exercise in the morning or early in the day. Take a walk, even if it is just around the house or your office during the day. </p></li>
<li><p>Consider starting with a protein-heavy breakfast, since <a href="https://doi.org/10.3945/ajcn.2008.26574">sleep deprivation can increase appetite</a> and <a href="https://doi.org/10.1016/j.appet.2018.02.013">craving for high-carbohydrate foods and sugars</a>.</p></li>
<li><p><a href="https://doi.org/10.5664/jcsm.9736">Stop using caffeine after noon</a>. Use of caffeine too late in the day can lead to trouble falling asleep and <a href="https://doi.org/10.1016/j.fct.2021.112549">even disrupted sleep</a>.</p></li>
<li><p>Adults, <a href="https://www.tandfonline.com/doi/abs/10.1300/J465v26n01_01">decline that wine at bedtime</a>. Wine and other kinds of alcohol <a href="https://doi.org/10.1016/j.hnm.2022.200140">can also disturb sleep</a>.</p></li>
<li><p>If you’re a parent or caregiver, try to be patient with your kids as they adjust to the new times. Sleep deprivation affects the entire family, and some kids have a harder time adjusting to the time change than others. You may notice more frequent <a href="https://doi.org/10.1016/j.acap.2017.02.001">meltdowns, irritability and loss of attention and focus</a>. Set aside more quiet, electronic media-free time in the evening. Consider a brief 20-minute nap in the early afternoon for younger children who are having a difficult time dealing with this change.</p></li>
</ol>
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<p>Prioritizing sleep pays off in the short term and over the years. A good night’s sleep is a necessary ingredient for a productive and fulfilling day all year long.</p>
<p><em>This is an updated version of <a href="https://theconversation.com/11-things-you-can-do-to-adjust-to-losing-that-1-hour-of-sleep-when-daylight-saving-time-starts-112938">an article</a> originally published on March 7, 2019.</em></p><img src="https://counter.theconversation.com/content/179154/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Deepa Burman is affiliated with American Board of Internal Medicine as a member of the Sleep Medicine Board Exam Test Question Writing Committee. </span></em></p><p class="fine-print"><em><span>Hiren Muzumdar does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Two sleep doctors offer some survival tips to help you adjust to losing that hour of sleep as clocks spring forward into daylight saving time.Deepa Burman, Co-Director Pediatric Sleep Evaluation Center and Associate Professor of Pediatrics, University of PittsburghHiren Muzumdar, Director of the Pediatric Sleep Evaluation Center, UPMC Children’s Hospital of Pittsburgh, University of PittsburghLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1754272022-03-10T13:26:13Z2022-03-10T13:26:13ZWhy daylight saving time is unhealthy – a neurologist explains<figure><img src="https://images.theconversation.com/files/446656/original/file-20220215-23-t2rtou.jpg?ixlib=rb-1.1.0&rect=0%2C11%2C7500%2C5018&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Changing clocks twice a year may be more than just a biannual annoyance.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/pink-alarm-clock-in-pastel-colorful-background-top-royalty-free-image/1152975326?adppopup=true">Carol Yepes/Moment via Getty Images</a></span></figcaption></figure><p>As people in the U.S. prepare to turn their clocks ahead one hour in mid-March, I find myself bracing for the annual ritual of <a href="https://www.inquirer.com/news/standard-time-daylight-saving-time-clock-change-sleep-20201031.html">media stories</a> about <a href="https://qz.com/1114163/daylight-saving-time-dst-is-incredibly-disruptive-heres-how-to-reset/">the disruptions to daily routines</a> caused by switching from standard time to daylight saving time. </p>
<p>About a third of Americans say they don’t look forward to these twice-yearly time changes. An overwhelming 63% to 16% majority <a href="https://today.yougov.com/topics/politics/articles-reports/2021/11/04/daylight-saving-time-americans-want-stay-permanent">would like to eliminate</a> them completely.</p>
<p>But the effects go beyond simple inconvenience. Researchers are discovering that “springing ahead” each March is connected with <a href="https://doi.org/10.1371/journal.pcbi.1007927">serious negative health effects</a>. </p>
<figure class="align-center ">
<img alt="An illustration of two clocks depicting Daylight Savings Time changes: Fall backward, and spring forward." src="https://images.theconversation.com/files/446653/original/file-20220215-13-1d96ozk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/446653/original/file-20220215-13-1d96ozk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=360&fit=crop&dpr=1 600w, https://images.theconversation.com/files/446653/original/file-20220215-13-1d96ozk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=360&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/446653/original/file-20220215-13-1d96ozk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=360&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/446653/original/file-20220215-13-1d96ozk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=452&fit=crop&dpr=1 754w, https://images.theconversation.com/files/446653/original/file-20220215-13-1d96ozk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=452&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/446653/original/file-20220215-13-1d96ozk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=452&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">At 2 a.m. on Sunday, March 13, 2022, clocks spring forward one hour. They fall back at 2 a.m. on Sunday, Nov. 6, 2022.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/illustration/daylight-saving-time-fall-backward-and-royalty-free-illustration/1356689682?adppopup=true">iam2mai/iStock via Getty Images Plus</a></span>
</figcaption>
</figure>
<p>I’m a <a href="https://scholar.google.com/citations?user=ZddlKEoAAAAJ&hl=en">professor of neurology and pediatrics</a> at Vanderbilt University Medical Center in Nashville, Tennessee, and the director of our sleep division. In a <a href="https://doi.org/10.1001/jamaneurol.2019.3780">2020 commentary</a> for the journal JAMA Neurology, my co-authors and I reviewed the evidence linking the annual transition to daylight saving time to <a href="https://doi.org/10.1016/j.sleep.2016.10.009">increased strokes</a>, <a href="https://doi.org/10.3390/jcm8030404">heart attacks</a> and <a href="https://doi.org/10.5664/jcsm.4938">teen sleep deprivation</a>. </p>
<p>Based on an extensive body of research, my colleagues and I believe that the science establishing these links is strong and that the evidence makes a good case for adopting permanent standard time nationwide – as <a href="https://energycommerce.house.gov/committee-activity/hearings/rescheduled-hearing-on-changing-times-revisiting-spring-forward-fall">I testified at a recent Congressional hearing</a>.</p>
<h2>Missing sleep, worse health</h2>
<p>“Falling back” – going from daylight saving time to standard time each November by turning the clocks back one hour – is relatively benign. While some people may feel thrown off balance and need a few weeks to recover, research hasn’t linked it to serious impacts on health. </p>
<p>Springing forward is harder on the body, however. This is because our clock time is moved an hour later; in other words, it feels like 7 a.m. even though our clocks say it is 8 a.m. So it’s a permanent shift to later morning light for almost eight months – not just for the day of the change or a few weeks afterward. This is particularly notable because morning light is valuable for helping to set the body’s natural rhythms: It <a href="https://doi.org/10.1038/s41598-018-36791-5">wakes us up and improves alertness</a>.</p>
<p>Although the exact reasons are not yet known, this may be due to light’s effects on increasing <a href="https://doi.org/10.1080/10253890.2020.1741543">levels of cortisol</a>, a hormone that modulates the <a href="https://doi.org/10.1038/s41574-019-0228-0">stress response</a> or the effect of light on the <a href="https://doi.org/10.1038/s41598-018-36791-5">amygdala</a>, a part of the brain involved in emotions.</p>
<p>In contrast, exposure to light later into the evening delays the brain’s release of melatonin, the hormone that promotes drowsiness. This can interfere with sleep and cause us to sleep less overall, and the effect can last even after most people adjust to losing an hour of sleep at the start of daylight saving time. </p>
<p>Because puberty also causes melatonin to be released later at night, meaning that teenagers have a delay in the natural signal that helps them fall asleep, adolescents are <a href="https://dx.doi.org/10.5664/jcsm.4938">particularly susceptible to sleep problems</a> from the extended evening light of daylight saving time. This shift in melatonin during puberty lasts into our 20s.</p>
<p>Adolescents also may be chronically sleep deprived due to school, sports and social activity schedules. For instance, many <a href="https://nces.ed.gov/pubs2020/2020006/index.asp">children start school around 8 a.m.</a> or earlier. This means that during daylight saving time, many young people get up and travel to school in pitch darkness.</p>
<h2>The “western edge” effect</h2>
<p>Geography can also make a difference in how daylight saving time affects people. One study showed that people living on the western edge of a time zone, who get light later in the morning and light later in the evening, <a href="https://doi.org/10.1016/j.jhealeco.2019.03.007">got less sleep</a> than their counterparts on the eastern edge of a time zone. </p>
<p>This study found that western edge residents had higher rates of obesity, diabetes, heart disease and <a href="https://theconversation.com/breast-cancer-risk-higher-in-western-parts-of-time-zones-is-electric-light-to-blame-85803">breast cancer</a>, as well as lower per capita income and higher health care costs. Other research has found that <a href="https://doi.org/10.1158/1055-9965.EPI-16-1029">rates of certain other cancers are higher</a> on the western edge of a time zone. </p>
<p>Scientists believe that these health problems may result from a <a href="https://doi.org/10.3389/fphys.2019.00944">combination of chronic sleep deprivation and “circadian misalignment”</a>. Circadian misalignment refers to a mismatch in timing between our biological rhythms and the outside world. In other words, the timing of daily work, school or sleep routines is based on the clock, rather than on the sun’s rise and set. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/84aWtseb2-4?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">This video takes a deeper dive – all the way back to 1895 – into the history of daylight saving time.</span></figcaption>
</figure>
<h2>A brief history of daylight saving time</h2>
<p><a href="https://blogs.loc.gov/teachers/2017/03/world-war-i-and-daylight-savings-time/">Congress instituted daylight saving time</a> during World War I and again during World War II, and <a href="https://www.mercurynews.com/2016/10/30/the-year-daylight-saving-time-went-too-far/">once again during the energy crisis of the early 1970s</a>. The idea was that having extra light later into the afternoon would save energy by decreasing the need for electric lighting. This idea has since been <a href="https://doi.org/10.1016/j.jebo.2014.03.012">proved largely inaccurate</a>, as heating needs may increase in the morning in the winter, while air conditioning needs can also increase in the late afternoon in the summer.</p>
<p>Another pro-daylight saving argument has been that <a href="https://doi.org/10.1162/REST_a_00547">crime rates</a> drop with more light at the end of the day. While this has been proved true, the change is very small, and <a href="https://theconversation.com/is-daylight-saving-time-worth-the-trouble-research-says-no-86739">the health effects appear to outweigh</a> the lower rates of crime.</p>
<p>After World War II, it was left to state governments to set the start and end dates for daylight saving time. Because this created many railroad scheduling and safety problems, however, Congress passed the Uniform Time Act in 1966. This law set the nationwide dates of daylight saving time from the last Sunday in April until the last Sunday in October. </p>
<p>In 2007, <a href="https://www.bts.gov/geospatial/daylight-savings-time">Congress amended the Uniform Time Act</a> to expand daylight saving time from the second Sunday in March to the first Sunday in November, dates that remain in effect today.</p>
<p>The law allows states and territories to opt out of daylight saving time, however. Arizona and Hawaii are on permanent standard time, along with Puerto Rico, the U.S. Virgin Islands, Northern Mariana Islands, Guam and American Samoa. Now, many other states are considering <a href="https://www.usatoday.com/story/news/nation/2021/11/04/daylight-saving-time-legislation-fall-back/6233980001/">whether to stop</a> falling back and springing ahead. </p>
<p>The question then becomes: Should they pick permanent daylight saving time or permanent standard time?</p>
<h2>The strong case for permanent standard time</h2>
<p>Americans are split on whether they <a href="https://today.yougov.com/topics/politics/articles-reports/2021/11/04/daylight-saving-time-americans-want-stay-permanent">prefer permanent daylight saving time</a> or <a href="https://apnorc.org/projects/dislike-for-changing-the-clocks-persists/">permanent standard time</a>. However, my colleagues and I believe that the health-related science for establishing permanent standard time is strong.</p>
<p>Standard time most closely approximates natural light, with the sun directly overhead at or near noon. In contrast, during daylight saving time from March until November, the natural light is shifted unnaturally by one hour later. </p>
<p>Based on abundant evidence that daylight saving time is unnatural and unhealthy, I believe we should abolish daylight saving time and adopt permanent standard time.</p>
<p>[<em>Understand new developments in science, health and technology, each week.</em> <a href="https://memberservices.theconversation.com/newsletters/?nl=science&source=inline-science-understand">Subscribe to The Conversation’s science newsletter</a>.]</p><img src="https://counter.theconversation.com/content/175427/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>I am listed on the endorsements page of Save Standard Time.
I provided an individual endorsement.
I do not receive any financial, grant, or other support from this organization.</span></em></p>By altering the body’s internal clock, ‘springing forward’ may contribute to an increase in heart attacks and strokes.Beth Ann Malow, Professor of Neurology and Pediatrics, Vanderbilt UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1709042021-11-04T14:34:35Z2021-11-04T14:34:35ZAnother problem with daylight saving time: The time change raises your risk of hitting deer on the road<figure><img src="https://images.theconversation.com/files/429596/original/file-20211101-13-17hk6iz.jpg?ixlib=rb-1.1.0&rect=0%2C52%2C2936%2C1964&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The likelihood of hitting a deer is highest during morning and evening twilight.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/young-deer-stands-by-a-roadside-near-treplin-germany-10-news-photo/1038049036">Patrick Pleul/Picture alliance via Getty Images</a></span></figcaption></figure><p>Daylight saving time ends in the U.S. and Canada on Nov. 5, 2023, and <a href="https://www.timeanddate.com/time/change/usa">most of us</a> will set our clocks back an hour. There is a long-running debate about the <a href="http://dx.doi.org/10.1136/bmjopen-2016-014319">benefit of the time change</a>, given how it <a href="https://doi.org/10.1016/j.cub.2007.10.025">disrupts humans’ circadian rhythms</a>, causing short-term stress and fatigue. </p>
<p>Another risk accompanying the time change is on the roads: As more people drive at dusk during an active time of year for deer, the number of deer-vehicle accidents rises.</p>
<p>Deer cause over 1 million motor vehicle accidents in the U.S. each year, <a href="https://www.ecologyandsociety.org/vol14/iss2/art15/">resulting in more than US$1 billion</a> in property damage, about 200 human deaths and 29,000 serious injuries. Property damage insurance claims average around $2,600 per accident, and the overall average cost, including severe injuries or death, is over $6,000.</p>
<p>While avoiding deer – as well as <a href="https://doi.org/10.1046/j.1523-1739.1996.10041059.x">moose, elk and other hoofed animals, known as ungulates</a> – can seem impossible if you’re driving in rural areas, there are certain times and places that are most hazardous, and so warrant extra caution.</p>
<p>Transportation agencies, working with scientists, have been developing ways to predict where deer and other ungulates enter roads so they can post warning signs or install fencing or wildlife passages under or over the roadway. Just as important is knowing when these accidents occur.</p>
<p>My former students <a href="https://scholar.google.com/citations?user=lwT82GcAAAAJ&hl=en">Victor Colino-Rabanal</a>, <a href="https://www.researchgate.net/profile/Wijesooriya-Arachchilage-Abeyrathna">Nimanthi Abeyrathna</a> and I have <a href="https://doi.org/10.1007/s10531-017-1458-x">analyzed over 86,000</a> <a href="https://doi.org/10.1016/j.jenvman.2021.112774">deer-vehicle collisions</a> involving white-tailed deer in New York state using police records over a three-year period. Here’s what our research and other studies show about timing and risk.</p>
<h2>Time of day, month and year matters</h2>
<p>The risk of hitting a deer varies by time of day, day of the week, the monthly lunar cycle and seasons of the year. </p>
<p>These accident cycles are partly a function of driver behavior – they are highest when traffic is heavy, drivers are least alert and driving conditions are poorest for spotting animals. They are also <a href="https://doi.org/10.1016/j.aap.2019.105365">affected by deer behavior</a>. Not infrequently, deer-vehicle accidents involve multiple vehicles, as startled drivers swerve to miss a deer and collide with a vehicle in another lane, or they slam on the breaks and are rear-ended by the vehicle behind.</p>
<figure class="align-center ">
<img alt="Car on road during the start of leaf colors with road sign reading: Caution: High Hit Area" src="https://images.theconversation.com/files/422438/original/file-20210921-19-1dprmmr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/422438/original/file-20210921-19-1dprmmr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/422438/original/file-20210921-19-1dprmmr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/422438/original/file-20210921-19-1dprmmr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/422438/original/file-20210921-19-1dprmmr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/422438/original/file-20210921-19-1dprmmr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/422438/original/file-20210921-19-1dprmmr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A sign warns of deer traffic on Route 16 in Franklin County, Maine.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/fall-foliage-route-16-deer-crossing-franklin-county-maine-news-photo/629562975">Education Images/Universal Images Group via Getty Images</a></span>
</figcaption>
</figure>
<p>In analyzing thousands of deer-vehicle collisions, we found that these <a href="https://doi.org/10.1007/s10531-017-1458-x">accidents occur most frequently</a> at dusk and dawn, when deer are most active and drivers’ ability to spot them is poorest. Only about 20% of accidents occur during daylight hours. Deer-vehicle accidents are eight times more frequent per hour of dusk than daylight, and four times more frequent at dusk than after nightfall.</p>
<p>During the week, accidents occur most frequently on days that have the most drivers on the road at dawn or dusk, so they are associated with work commuter driving patterns and social factors such as Friday “date night” traffic.</p>
<p><a href="https://doi.org/10.1007/s10531-017-1458-x">Over the span</a> of a month, the most deer-vehicle accidents occur during the full moon, and at the time of night that the moon is brightest. Deer move greater distances from cover and are more likely to enter roadways when there is more illumination at night. The pattern holds for deer and other ungulates in both North America and <a href="https://doi.org/10.1046/j.1523-1739.1996.10041059.x">Europe</a>.</p>
<p><iframe id="Emy0i" class="tc-infographic-datawrapper" src="https://datawrapper.dwcdn.net/Emy0i/5/" height="400px" width="100%" style="border: none" frameborder="0"></iframe></p>
<p>Over a year, by far the highest numbers of deer-vehicle accidents are in autumn, and particularly during the rut, when bucks search and compete to mate with does. In New York state, the peak number of deer-vehicle accidents occurs in the <a href="https://doi.org/10.1016/j.jenvman.2021.112774">last week of October and first weeks of November</a>. There are over four times as many deer-vehicle accidents during that period as during spring. <a href="https://doi.org/10.1016/j.aap.2019.105365">Moose-vehicle accidents show a similar pattern</a>.</p>
<h2>The problem with daylight saving time</h2>
<p>We have also found that the daylight saving time clock shift of one hour <a href="https://doi.org/10.1016/j.jenvman.2021.112774">affects the number of deer-vehicle accidents</a>. </p>
<p>In spring, when deer-vehicle accidents are at an annual low, the start of daylight saving time means a later sunrise and sunset. It results in a small decrease in deer-vehicle accidents. However, in fall, when deer-vehicle accidents are at an annual high because of deer rut, the earlier sunrise and sunset cause a significant increase in deer-vehicle accidents. </p>
<p>The clock shift results in more commuters on the road during the high-risk dusk hours. The consequence is more cars driving at the peak time of day and during the peak time of the year for deer-vehicle accidents. The clock shift results in a 37% reduction in deer-vehicle accidents during morning commuter hours, since fewer commuters are on the road before sunrise, but a 72% increase in accidents during evening commuter hours. Overall, there is a 19% increase in accidents during commuter hours the week after the fall time change in New York.</p>
<h2>Deer still cross roads at any time</h2>
<p>It’s important to remember that deer-vehicle accidents can occur at any time of day or night, on any day of the year – and that deer can show up in urban areas as well as rural ones.</p>
<p>The insurance company State Farm found that on average, U.S. drivers have a <a href="https://newsroom.statefarm.com/animal-collision/">1 in 116 chance of hitting an animal</a>, with much higher rates in states such as West Virginia, Montana and Pennsylvania. Over the 12 months ended in June 2020, State Farm counted 1.9 million insurance claims for collisions with wildlife nationwide. <a href="https://www.fhwa.dot.gov/publications/research/safety/08034/exec.cfm">Around 90% of those involved deer</a>.</p>
<p>Where deer or other ungulates are likely to be present, drivers should always be alert and cautious, especially at dawn, dusk, on bright moonlit nights and during the fall rut. In addition, drivers should be aware that after the fall time change, they may be more fatigued, and their evening commute from work may have shifted into the dusk hours, when risk of hitting a deer is highest, and coinciding with the rut, when the risk is at its annual peak. </p>
<p><em>This is an update to an <a href="https://theconversation.com/fall-means-more-deer-on-the-road-4-ways-time-of-day-month-and-year-raise-your-risk-of-crashes-167489">article</a> originally published on Sept. 21, 2021.</em></p><img src="https://counter.theconversation.com/content/170904/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Tom Langen does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Dusk is a dangerous time of day for hitting wildlife on the road, and the one-hour time change means more drivers are out while deer are at their most active and visibility is dropping.Tom Langen, Professor of Biology, Clarkson UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1469562020-10-28T18:59:30Z2020-10-28T18:59:30ZDaylight saving time could be especially hard this weekend because of COVID-19 sleep loss<figure><img src="https://images.theconversation.com/files/389136/original/file-20210311-19-1mzgc1.jpg?ixlib=rb-1.1.0&rect=0%2C249%2C5357%2C3148&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption"> Sleep loss was an issue even before COVID-19. </span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/news-photo/107693557?adppopup=true">Thurston Hopkins/Picture Post/Hulton Archive via Getty Images</a></span></figcaption></figure><p>The clock springs forward one hour on Sunday morning, March 14 for most people in the U.S. That is not an appealing thought for those who have suffered sleep problems because of the pandemic. </p>
<p>Sleep this past year has been affected by a variety of factors, including anxiety, inconsistent schedules and increased screen time. This affects our health, as getting adequate sleep is important to assure our immune system can fend off and fight infections. </p>
<p>Even before the pandemic, about 40% of adults – 50 to 70 million Americans – <a href="https://doi.org/%2010.17226/11617">got less than the recommended</a> minimum seven hours per night.</p>
<p>And, many researchers were already concerned about how the twice-a-year switch affects our body’s physiology. <a href="https://doi.org/10.5664/jcsm.8780">The American Academy of Sleep Medicine</a>, the largest scientific organization that studies sleep, in October 2020 suggested nixing daylight saving time and moving to a year-round fixed time. That way, our internal circadian clocks would not be misaligned for half the year. And it would eliminate the safety risk from sleep loss when transitioning to daylight saving time.</p>
<p><a href="https://neurology.ufl.edu/profile/jaffee-michael/">I am a neurologist</a> at the University of Florida. I’ve studied how a lack of sleep can impair the brain. In the 1940s, most American adults averaged 7.9 hours of sleep a night. Today, it’s only 6.9 hours. To put it another way: In 1942, 84% of us got the recommended seven to nine hours; in 2013, it was 59%. To break it down further, a January <a href="https://blog.fitbit.com/sleep-study/">2018 study from Fitbit</a> reported that men got even less sleep per night than women, about 6.5 hours. </p>
<figure class="align-center ">
<img alt="A 6-year-old needs 9-12 hours of sleep a day." src="https://images.theconversation.com/files/365135/original/file-20201023-15-1stabfx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/365135/original/file-20201023-15-1stabfx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/365135/original/file-20201023-15-1stabfx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/365135/original/file-20201023-15-1stabfx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/365135/original/file-20201023-15-1stabfx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/365135/original/file-20201023-15-1stabfx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/365135/original/file-20201023-15-1stabfx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Children age 12 and under need 9-12 hours of sleep per night.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/boy-sleeping-in-bed-royalty-free-image/630159689?adppopup=true">Tetra Images/DigitalVision via Getty Images</a></span>
</figcaption>
</figure>
<h2>The case for sleep</h2>
<p>Problems from sleep shortage go beyond simply being tired. Compared to those who got enough sleep, adults who are short sleepers – those getting less than seven hours per day – <a href="https://www.nichd.nih.gov/health/topics/sleep/conditioninfo/inadequate-sleep">were more likely to report</a> 10 chronic health conditions, including heart disease, diabetes, obesity, asthma and depression. </p>
<p>Children, who need more sleep than adults, face even more challenges. <a href="https://jcsm.aasm.org/doi/10.5664/jcsm.5866">To promote optimal health</a>, 6- to 12-year-olds should sleep nine to 12 hours a day; teens from 13 to 18, eight to 10 hours. But a Sleep Foundation poll of parents says children are getting at least one hour less than that. And <a href="https://doi.org/10.1093/sleep/30.9.1079">researchers have found</a> that sleep deprivation of even a single hour can harm a child’s developing brain, affecting memory encoding and attentiveness in school.</p>
<p>Sleep affects <a href="https://theconversation.com/why-are-we-so-sleep-deprived-and-why-does-it-matter-91803">every one of our biological systems</a>. Serious consequences can result with poor sleep quality. Here’s a short list: <a href="https://doi.org/10.1378/chest.09-2954">Blood pressure</a> may increase. <a href="https://doi.org/%2010.2174/157340310790231635">Risk of coronary heart disease</a> could go up. Our endocrine system releases more cortisol, a stress hormone. We become more aroused by “fight or flight” syndrome. There’s a reduction of growth hormone and muscle maintenance. There’s a higher chance of increased appetite and weight gain. The body has less glucose tolerance and greater insulin resistance; in the long term, that means an increased risk for Type 2 diabetes. </p>
<p>Sleep deprivation is associated with increased inflammation and a decreased number of antibodies to fight infections. It may also cause a decrease in pain tolerance, reaction times and memory. Occupational studies show sleep loss can cause poor work performance, including more days missed and more car accidents.</p>
<p><a href="https://doi.org/10.1016/j.cophys.2019.10.020">Recent research suggests</a> the body’s waste removal process relies on sleep to get rid of harmful proteins from the brain, particularly abnormal variants of amyloid. These are the same proteins that are elevated in Alzheimer’s patients. <a href="https://www.alzforum.org/news/research-news/lymphatic-brain-drain-withers-aging-worsens-disease">Studies show</a> that older adults who sleep less have greater accumulation of these proteins in their brains.</p>
<p>On the other hand, getting enough sleep helps the body in many ways by protecting against some of these damaging effects and by boosting the immune system.</p>
<figure class="align-center ">
<img alt="Some educators worry about transporting schoolchildren at dusk." src="https://images.theconversation.com/files/365140/original/file-20201023-15-1lg3bgv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/365140/original/file-20201023-15-1lg3bgv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/365140/original/file-20201023-15-1lg3bgv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/365140/original/file-20201023-15-1lg3bgv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/365140/original/file-20201023-15-1lg3bgv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/365140/original/file-20201023-15-1lg3bgv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/365140/original/file-20201023-15-1lg3bgv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Some educators worry about the safety factor when transporting schoolchildren at dusk.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/diverse-group-of-happy-children-getting-on-school-royalty-free-image/1166892600?adppopup=true">FatCamera/E+/E+ via Getty Images</a></span>
</figcaption>
</figure>
<h2>The problem with DST</h2>
<p>Most of the risk associated with daylight saving time occurs in the spring, when we turn the clock forward and lose one hour of sleep. The idea of a national permanent year-round time has support, but disagreements exist on whether the fixed time should be standard time or daylight saving time.</p>
<p>[<em>Deep knowledge, daily.</em> <a href="https://theconversation.com/us/newsletters/the-daily-3?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=deepknowledge">Sign up for The Conversation’s newsletter</a>.]</p>
<p><a href="https://www.ncsl.org/research/transportation/daylight-savings-time-state-legislation.aspx">States advocating</a> for permanent daylight saving time are typically those that rely on tourism. Environmentalists, favoring less energy consumption from morning heating and evening air conditioning, <a href="https://savestandardtime.com/pdfs/kotchen_and_grant-2008_12.pdf">often support permanent standard time</a>. Religious groups, whose prayer times are linked to sundown and sunrise, <a href="https://vosizneias.com/2018/03/13/miami-floridas-proposed-change-to-permanent-daylight-savings-time-could-create-halachic-problems-for-jewish-community/">also tend to prefer</a> permanent standard time. <a href="https://savestandardtime.com/pdfs/mercury_news-2018.pdf">So do many educators</a>, opposed to transporting children to school during mornings when it’s still dark. </p>
<p>As you ponder what system is best for a national year-round standard, consider this: The American Academy of Sleep Medicine has recommended we go with permanent standard time – a better way to align with our natural circadian clock and minimize health and safety risks.</p>
<p>And just think: If we change to permanent standard time, then for the first time in decades, you won’t lose an hour of sleep every spring.</p>
<p><em>Editor’s note: This story is updated from its original version, which was published Oct. 28, 2020.</em></p><img src="https://counter.theconversation.com/content/146956/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michael S. Jaffee does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Springing forward for daylight saving time will be especially hard this year due to sleep loss from COVID-19. Why does the US keep doing this?Michael S. Jaffee, Vice Chair, Department of Neurology, University of FloridaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1285242020-03-30T18:48:24Z2020-03-30T18:48:24ZCoronavirus: Social distancing may be a rare chance to get our sleep patterns closer to what nature intended<figure><img src="https://images.theconversation.com/files/322026/original/file-20200320-22590-ql9fa9.jpg?ixlib=rb-1.1.0&rect=66%2C0%2C7282%2C4792&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Spending more time in bed and letting your body's natural rhythms take over could be good for your health.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/young-african-woman-sleeping-her-bed-554782891">Stock-Asso/Shutterstock.com</a></span></figcaption></figure><p>The COVID-19 pandemic is disrupting daily routines around the world. Overwhelmed hospitals, desolate schools, ghostly towns and self-isolation echo a campy horror flick, but an all too real one.</p>
<p>Companies are <a href="https://www.washingtonpost.com/business/2020/03/19/unemployment-insurance-today-coronavirus/">laying people off</a> by the thousands, the service industry is teetering on the brink of collapse, and <a href="https://www.nytimes.com/2020/03/18/business/economy/coronavirus-evictions.html?action=click&module=Top%20Stories&pgtype=Homepage">socialist ideas suddenly don’t sound so bad to an average citizen </a>. According to a recent poll by the University of Southern California, around <a href="https://www.mercurynews.com/2020/03/13/coronavirus-poll-shows-how-americans-are-changing-behavior/">40% of individuals feel anxiety</a> about the pandemic, and more than half have been avoiding some or all other people. </p>
<p>As a <a href="https://scholar.google.com/citations?hl=en&user=CPsb1PoAAAAJ">psychologist</a> who aims to understand the role of sleep in what makes us tick, I focus mostly on how the sleep-wake cycle impacts our day-to-day social lives. Which makes me think of one thing thing we can do, especially for those of us at home. That is to sleep. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/322034/original/file-20200320-22627-1petg6e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/322034/original/file-20200320-22627-1petg6e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=425&fit=crop&dpr=1 600w, https://images.theconversation.com/files/322034/original/file-20200320-22627-1petg6e.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=425&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/322034/original/file-20200320-22627-1petg6e.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=425&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/322034/original/file-20200320-22627-1petg6e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=534&fit=crop&dpr=1 754w, https://images.theconversation.com/files/322034/original/file-20200320-22627-1petg6e.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=534&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/322034/original/file-20200320-22627-1petg6e.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=534&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Turning off alarm clocks and phones can allow your body to sleep according to its natural circadian rhythm.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/top-view-bed-night-attractive-young-1427337872">Gorondenkof/Shutterstock.com</a></span>
</figcaption>
</figure>
<h2>Sleep at the dawn of COVID-19</h2>
<p>This reversible state of disengagement with the world is one of the most important protective and restorative factors in human life. Slumber is essential for thinking clearly and staying upbeat <a href="https://doi.org/10.1177/1745691615598509">during any time </a>. Moreover, sleep is indispensable for maintaining immunological function, which is key to preventing and <a href="https://doi.org/10.1152/physrev.00010.2018">recovering from infectious diseases like COVID-19 </a>. Losing sleep makes people more susceptible to viral infections, and it undermines recovery from the common cold as well as <a href="https://doi.org/%2010.1001/archinternmed.2008.505">more serious conditions </a>. For this lethally stealthy bug, it may be even more important. </p>
<p>Unfortunately, it is exactly during times of social uncertainty and anxiety, when we need sleep the most, that it is most disrupted. Anxiety over the future and fear for health of loved ones threaten calm nights and impinge on sleep by increasing hyper-arousal and rumination – reactions known to <a href="https://www.mayoclinic.org/diseases-conditions/insomnia/symptoms-causes/syc-20355167">intensify insomnia </a>. Isolation from regular social rhythms and natural light will further mess with our body clock, confusing us about when we are <a href="https://doi.org/10.1007/s11818-019-00215-x">supposed to feel tired and when to perk up</a>. </p>
<p>Most Americans are not meeting this crisis well-rested. Research we have conducted over the past few years using CDC data on hundreds of thousands of Americans suggests that the smart phone age has led to <a href="https://www.news.iastate.edu/news/2017/10/19/smartphonesleep">substantial deterioration in both duration and quality of sleep</a>. A case in point, a recent analysis that my team conducted suggests that over the past five years, <a href="https://www.yahoo.com/lifestyle/nearly-five-million-americans-struggling-161805004.html">millions more Americans</a> report sleeping problems. </p>
<p>And the psychological toll is not too far away, but it will register most forcefully after the infection rates start to decline. Once the pandemic peaks and the physical damage to bodies start to wane, only then will the full consequences of this pandemic on our well-being be apparent. Inevitable increases in psychological complaints, suicide, and substance use disorders need to be anticipated and mitigated now. Recall that after the “Great Recession” of 2008-09 there were <a href="https://www.sciencedaily.com/releases/2018/03/180301094841.htm;%20https://www.npr.org/sections/krulwich/2014/06/11/318885533/suicide-rate-in-u-s-and-europe-climbed-during-great-recession">millions more people with health and psychological problems in both U.S. and Europe</a>.</p>
<p>So how to go about protecting our sleep? Besides the threats and challenges, this time actually provides hidden opportunities as well. When is the last time that the majority of any population stayed at home for days, often without need to use alarm clocks?! </p>
<p>Besides connecting with those closest to us, many of us can sleep in and organize lives in ways that suit our biological ticker. Larks can go to bed earlier and owls can snooze in. Families can synchronize their meal and play routines in new ways, honoring the time of their internal clock (what chrono-biologists call the <a href="https://www.sleepfoundation.org/articles/what-circadian-rhythm">‘circadian’ phase’</a>).
For most of our history we slept with one another when our bodies told us too, <a href="https://www.nytimes.com/2017/03/01/books/wild-nights-benjamin-reiss.html">not by ourselves and only when work allowed</a>. This may be an unprecedented opportunity to embrace a basic human need to switch off on a regular basis, helping human bodies fight the wars only those bodies know how. </p>
<p>[<em>Get facts about coronavirus and the latest research.</em> <a href="https://theconversation.com/us/newsletters?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=upper-coronavirus-facts">Sign up for our newsletter.</a>]</p><img src="https://counter.theconversation.com/content/128524/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Zlatan Krizan has received funding from the National Science Foundation, Federal Bureau of Investigation, and the Minnesota Department of Transportation.</span></em></p>The time at home from the coronavirus crisis could be an opportunity to let our natural sleep rhythms take over.Zlatan Krizan, Professor of Psychology, Iowa State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1257562019-10-24T10:37:44Z2019-10-24T10:37:44ZHow daylight saving time can mess with financial markets<figure><img src="https://images.theconversation.com/files/298372/original/file-20191023-119477-1692e5v.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>A number of studies show that daylight savings time harms people’s decision making processes due to the disturbance it has on their circadian rhythm or body clock. For example, research <a href="https://psychcentral.com/lib/daylight-savings-time-and-mental-health/">finds</a> that people experience more pronounced mood swings shortly after daylight saving time ends. After daylight saving time is introduced there are <a href="https://www.ncbi.nlm.nih.gov/pubmed/29223028">more car accidents</a> and more people tend to experience <a href="https://theconversation.com/daylight-savings-is-linked-to-injuries-and-heart-attacks-is-it-time-to-scrap-it-49672">health complications</a>.</p>
<p>It turns out that the clock change can also have an effect on financial markets. In <a href="https://www.sciencedirect.com/science/article/pii/S0378426619301190">my research</a> I’ve found that investor decision making is affected following clock changes. </p>
<p>Looking at the stock performance of companies targeted for mergers in the wake of the merger being announced, I found that stocks in these companies on average went up more than normal and were more volatile the first trading day after clock changes. After all, even professional investors are human and daylight saving time influences their decisions as much as anyone else’s, regardless of their qualifications and experience.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/daylight-savings-is-linked-to-injuries-and-heart-attacks-is-it-time-to-scrap-it-49672">Daylight savings is linked to injuries and heart attacks, is it time to scrap it?</a>
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<p>Daylight saving time is used by a number of countries including the US, UK and across Europe. Here the clocks are moved forward by an hour at the start of spring to increase the amount of sunlight in the evenings. They are then put back again ahead of winter, increasing the amount of sunlight in the mornings and causing sunset to take place earlier. The one hour time difference seems to have a surprisingly large effect on people’s sleep patterns and behaviour, as a result.</p>
<h2>Mood swings, risk taking</h2>
<p>To explore the effect on financial markets, I studied the stock returns of more than 5,500 firms targeted for mergers between 1977 and November 2017 in the US – 90 of these mergers were announced on a Monday after or over the weekend of a daylight saving time change. I looked at mergers because these are typically unexpected events – hence there is generally significant investor reaction to these announcements. Leaks and rumours were controlled for, as well as a number of other factors like company size. </p>
<p>When a merger is announced, the target firm experiences, on average, <a href="https://www.jstor.org/stable/40388691">returns of 10% on the announcement</a>. This is because a merger is generally good news for their shareholders. But when a merger is announced over a weekend or on a Monday following daylight saving time, the average stock return went up by around 2.50% more in relation to announcements that took place on other days – a statistically significant increase in profits for the target firms.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/298371/original/file-20191023-119414-1u4q7bl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/298371/original/file-20191023-119414-1u4q7bl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/298371/original/file-20191023-119414-1u4q7bl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/298371/original/file-20191023-119414-1u4q7bl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/298371/original/file-20191023-119414-1u4q7bl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/298371/original/file-20191023-119414-1u4q7bl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/298371/original/file-20191023-119414-1u4q7bl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Sleep disruption makes investors bullish.</span>
<span class="attribution"><span class="source">Life In Pixels/Shutterstock</span></span>
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</figure>
<p>Based on the controls, this change can be attributed to the disrupted sleep patterns of investors, making them overreact to the information available to them in the short term. With <a href="https://www.ncbi.nlm.nih.gov/pubmed/23286526">plenty of evidence</a> that investors experience relatively stronger mood swings and higher risk-taking behaviour when their circadian rhythm is disturbed, it seems as though daylight saving time causes investors to push the stock prices of target firms to more extreme values. </p>
<h2>Time to scrap it?</h2>
<p>In March 2019 the European parliament <a href="https://www.theguardian.com/world/2019/mar/26/european-parliament-votes-to-scrap-daylight-saving-time-from-2021">voted to scrap</a> daylight savings time. The motion seemed to have widespread support – it passed by 410 votes to 192 and 84% of the 4.6m responses to its survey on the matter were in favour of the move. But a vocal minority oppose the change, including the UK’s <a href="https://www.thesun.co.uk/news/8072041/daylight-saving-time-eu-plans-fight/">Conservative government</a>. </p>
<p>These results add to this debate surrounding the usefulness of daylight saving time and whether or not it should be scrapped. As well as being bad for people’s health, it seems the clock change also has an undue effect on financial markets.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-ancient-clock-that-rules-our-lives-and-determines-our-health-85034">The ancient clock that rules our lives – and determines our health</a>
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<p>My study also shows how even moderate changes in sleep patterns can influence investment decisions. Our individual sleep patterns may vary a lot more than just one hour on a daily basis, which raises concerns about how our sleep may influence our decision making. </p>
<p>Of course, this is especially important for investment professionals. The development of sleep hygiene courses, the availability of flexible working hours to match people’s sleep preferences (<a href="https://theconversation.com/morning-lark-or-night-owl-how-our-body-clocks-affect-our-mental-and-physical-performance-106486">whether you’re a night owl or an early bird</a>), and the installation of high grade lighting and sleep pods in offices are some of the ways firms can take steps to improve sleep for their staff.</p><img src="https://counter.theconversation.com/content/125756/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Antonios Siganos does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Research shows how decision making by investors is affected by the one-hour clock change.Antonios Siganos, Senior Lecturer in Finance, University of GlasgowLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1238712019-09-30T02:47:19Z2019-09-30T02:47:19Z6 ways to stop daylight saving derailing your child’s sleep<figure><img src="https://images.theconversation.com/files/294002/original/file-20190925-51401-1gw3tru.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">It's harder for kids to get to sleep when it's light outside and they're not as tired.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/young-mother-her-2-years-old-322337936?src=JpbwHINXJDdLiO4qQZeb-A-3-10">Alena Ozerova/Shutterstock</a></span></figcaption></figure><p>Daylight saving will begin this weekend across most of Australia, signalling warmer weather, longer days and new opportunities for children to make the most of time outside.</p>
<p>It can also mark the start of a rough patch in the sleep department. Children’s body clocks can struggle to adjust as the hour shift forwards means they aren’t tired until later.</p>
<p>There are things parents can do to ease the transition to daylight saving and planning ahead is key. And if things get wobbly, there are also strategies to get them back on track.</p>
<p>But first, let’s look at where the problem starts. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/spring-forward-fall-back-how-daylight-saving-affects-our-sleep-25025">Spring forward, fall back: how daylight saving affects our sleep</a>
</strong>
</em>
</p>
<hr>
<h2>Children’s body clocks</h2>
<p>The body clock – also known as our circadian rhythm – controls when we sleep and wake. </p>
<p>Several environmental cues affect our body clock, the most common of which is the light-dark cycle. When it’s dark, our bodies produce more of the hormone melatonin, which helps bring on sleep. And when it’s light, our bodies produce less, so we feel more awake.</p>
<p>When daylight saving begins, children’s bodies aren’t getting the usual environmental signals to sleep at their regular time. </p>
<p>But a later bedtime means getting less sleep overall, which can <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3100528/">impact on</a> their concentration, memory, behaviour and <a href="https://www.ncbi.nlm.nih.gov/pubmed/19403493">ability to learn</a>.</p>
<p>So, how do you plan for the daylight saving switchover?</p>
<h2>1. Take a sleep health check</h2>
<p>This is a good opportunity to look at how your child is sleeping and whether they’re <a href="https://www.ncbi.nlm.nih.gov/pubmed/24347573">getting enough sleep</a> overall. Individual needs will vary but <a href="https://raisingchildren.net.au/toddlers/sleep/understanding-sleep/about-sleep">as a guide</a>, here’s what you should aim for:</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/294713/original/file-20190930-185364-qk9ng6.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/294713/original/file-20190930-185364-qk9ng6.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/294713/original/file-20190930-185364-qk9ng6.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=285&fit=crop&dpr=1 600w, https://images.theconversation.com/files/294713/original/file-20190930-185364-qk9ng6.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=285&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/294713/original/file-20190930-185364-qk9ng6.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=285&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/294713/original/file-20190930-185364-qk9ng6.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=359&fit=crop&dpr=1 754w, https://images.theconversation.com/files/294713/original/file-20190930-185364-qk9ng6.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=359&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/294713/original/file-20190930-185364-qk9ng6.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=359&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
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</figure>
<p>Most children wake themselves in the morning, or wake easily with a gentle prompt, if they’re getting enough good-quality sleep.</p>
<p>But <a href="https://raisingchildren.net.au/toddlers/sleep/sleep-problems/sleep-problems-solutions">sleep problems</a> such as trouble getting to sleep and staying asleep are common and persistent. <a href="https://www.ncbi.nlm.nih.gov/pubmed/19403493">Around 50% of problems that begin before a child starts school</a> continue into the early school years. So, early intervention makes a difference.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/sleep-problems-that-persist-could-affect-childrens-emotional-development-62433">Sleep problems that persist could affect children's emotional development</a>
</strong>
</em>
</p>
<hr>
<h2>2. Review the bedtime routine</h2>
<p>As well as the light-dark cycle, children’s circadian rhythms are synchronised with other environmental cues, such as timing around bath and dinner. A positive routine in the hour before bed creates consistency the body recognises, helping children wind down in preparation for sleep.</p>
<p>Bedtime routines work best when the atmosphere is calm and positive. They include a bath, brushing teeth and quiet play – like reading with you – some quiet chat time, and relaxing music. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/293993/original/file-20190925-51452-eqqpbd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/293993/original/file-20190925-51452-eqqpbd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/293993/original/file-20190925-51452-eqqpbd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/293993/original/file-20190925-51452-eqqpbd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/293993/original/file-20190925-51452-eqqpbd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/293993/original/file-20190925-51452-eqqpbd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/293993/original/file-20190925-51452-eqqpbd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Reading stories before bed is calming and helps create a predicable routine.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/father-reading-story-daughter-bedtime-627689348?src=l6O-sF_-S4IRB1uXjao6vg-1-31">Shutterstock</a></span>
</figcaption>
</figure>
<p>Keeping quiet time consistent makes it easier to say goodnight and lights out. Doing a quick check on whether they’ve had a drink, been to the toilet and so on can help address things they might call out for later. </p>
<p>Gently reminding children what you expect and quiet praise for staying in bed helps too.</p>
<h2>3. Keep regular sleep and wake times</h2>
<p>Sticking to similar daily bedtimes and wake times keeps children’s circadian rhythms in a regular pattern. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/regular-bed-times-as-important-for-kids-as-getting-enough-sleep-19396">Regular bed times as important for kids as getting enough sleep</a>
</strong>
</em>
</p>
<hr>
<p>It’s best to keep this routine during weekends and holidays – even though these are times when older children in particular are eager for later nights. This is worth remembering to avoid a double whammy of sleep disruption as daylight saving and the school holidays coincide. </p>
<p>If your child is not tiring until later, try making bedtime 15 minutes earlier each day until you reach your bedtime target. </p>
<h2>4. Control the sleep environment</h2>
<p>Darkening the room is an important cue to stimulate melatonin production. This can be challenging during daylight saving, depending on your home. Trying to block out light – say, with thicker curtains – is a good strategy. Keeping the amount of light in the room consistent will also make for better sleep.</p>
<p><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4437561/">Research suggests</a> the blue light emitted by screens from digital devices might suppress melatonin and delay sleepiness. It’s advisable to turn screens off at least an hour before bed and to keep them out of the bedroom at night.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/293999/original/file-20190925-51401-rviy69.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/293999/original/file-20190925-51401-rviy69.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/293999/original/file-20190925-51401-rviy69.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/293999/original/file-20190925-51401-rviy69.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/293999/original/file-20190925-51401-rviy69.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/293999/original/file-20190925-51401-rviy69.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/293999/original/file-20190925-51401-rviy69.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Turn screens off an hour before bed.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/1018547617?src=3QMkr6RlCUPtb0ETFbcmBA-1-0&size=huge_jpg">Ternavskaia Olga Alibec/Shutterstock</a></span>
</figcaption>
</figure>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/wired-and-tired-why-parents-should-take-technology-out-of-their-kids-bedroom-50406">Wired and tired: why parents should take technology out of their kid's bedroom</a>
</strong>
</em>
</p>
<hr>
<p>Temperature plays a role in priming children for sleep, as core body temperature decreases in sync with the body clock. So, check the room, bedding or clothing aren’t too hot. Between 18°C and 21°C is the ideal temperature range for a child’s bedroom.</p>
<h2>5. Consider what happens during the day</h2>
<p>Making sure your child gets plenty of natural daylight, especially in the morning, keeps them alert during the day and sleepy in the evening. </p>
<p>Daytime physical activity also makes children tired and ready for a good night’s sleep.</p>
<p>For children over five, keep naps early and short (20 minutes or less) because longer and later naps make night sleep harder. </p>
<p>For younger children, too little daytime sleep can make them overtired and therefore harder to settle into bed.</p>
<h2>6. Focus on food and drink</h2>
<p>Think about dinner timing because feeling hungry or full before bedtime can delay sleep by making children too alert or uncomfortable. </p>
<p>It’s also important to avoid caffeine in the late afternoon and evening. Caffeine is in chocolate, energy drinks, coffee, tea and cola. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/kids-diets-and-screen-time-to-set-up-good-habits-make-healthy-choices-the-default-at-home-114827">Kids' diets and screen time: to set up good habits, make healthy choices the default at home</a>
</strong>
</em>
</p>
<hr>
<p>In the morning, a healthy breakfast helps kick-start your child’s body clock at the right time.</p>
<p>Finally, worries, anxiety, and common illnesses can also cause sleep problems. If problems last beyond two to four weeks, or you’re worried, see your GP.</p><img src="https://counter.theconversation.com/content/123871/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Associate Professor Julie Green is Executive Director of the Australian parenting website raisingchildren.net.au which receives funding from the Australian government.
Julie is a Director of the Parenting Research Centre. She is a co-investigator on one Australian Research Council Discovery Project grant and one National Health & Medical Research Council project grant.
</span></em></p><p class="fine-print"><em><span>Jon Quach receives funding from the Australian Research Council and National Health Medical Research Council. He is affiliated with Sleep Health Foundation.
</span></em></p>Daylight saving time starts this weekend, and it can often be the beginning of new dramas getting kids to bed. Here’s how to make the transition a little smoother.Julie Green, Principal Fellow, Murdoch Children's Research InstituteJon Quach, Research fellow, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1166302019-05-07T11:21:17Z2019-05-07T11:21:17ZThe hazards of living on the right side of a time zone border<figure><img src="https://images.theconversation.com/files/272931/original/file-20190507-103082-1th9f5q.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Daylight saving time is an artificial way of adjusting time, but nothing changes when the sun rises and sets. </span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/vintage-sundial-green-patina-throws-long-1115549564?src=JaUSpZOE8GZWcCsJoYcbOA-1-1">Jerry Regis/Shutterstock.com</a></span></figcaption></figure><p>The sun both rises and sets later in the western parts of time zones, by about an hour at the extremes. If sunrise in Nashville, Tennessee is 6:30 a.m., it’s about 7:30 a.m. in Amarillo, Texas. Similarly, if sunset in Nashville is 8 p.m., it’s about 9 p.m. in Amarillo. Yet both are in the Central time zone.</p>
<p>This means that many people in Amarillo must get up before sunrise to get to work on time compared to people in Nashville, who can get up after sunrise. As I reported previously, <a href="https://theconversation.com/breast-cancer-risk-higher-in-western-parts-of-time-zones-is-electric-light-to-blame-85803">two studies</a> have shown that breast cancer risk is higher in the western parts of time zones; the first was conducted in European Russia and the second in the U.S. The authors of these two studies suggest it is the chronic disruption of circadian rhythms from getting up in the dark that may be the culprit.</p>
<p>However, the good part to living in the west is that there is an hour more daylight after work in Amarillo than in Nashville. That’s been part of the campaign for a <a href="https://theconversation.com/5-ways-life-would-be-better-if-it-were-always-daylight-saving-time-111506">permanent daylight saving time</a> – an hour more fun in the sun in the evening under DST.</p>
<p>However, a buzzkill new study has just reported health problems with a later clock time of sunset as well, and it’s not just breast cancer. </p>
<h2>Social jet lag</h2>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/272927/original/file-20190507-103045-x9hes8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/272927/original/file-20190507-103045-x9hes8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/272927/original/file-20190507-103045-x9hes8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/272927/original/file-20190507-103045-x9hes8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/272927/original/file-20190507-103045-x9hes8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/272927/original/file-20190507-103045-x9hes8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/272927/original/file-20190507-103045-x9hes8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Early start times for school and work can not only cause sleepiness but may also contribute to disease, studies suggest.</span>
<span class="attribution"><span class="source">Phovoir/Shutterstock.com</span></span>
</figcaption>
</figure>
<p>Writing in the Journal of Health Economics, authors Osea Giuntella of the University of Pittsburgh and Fabrizio Mazzonna of Università della Svizzera Italiana took an innovative slant on the <a href="https://www.sciencedirect.com/science/article/pii/S0167629618309718">effect of position in a time zone</a> on health and economics. They were interested in something called “<a href="https://www.cosmopolitan.com/uk/body/health/a22715169/what-is-social-jet-lag/">social jet lag.”</a> </p>
<p>The idea is that given the constraints of modern life, most people are out of sync with their natural circadian rhythms, which should follow the sun. Instead, we use electric light to synchronize most of our societal activities regardless of where the sun is at in its course through the heavens.</p>
<p>The conflict is that the primordial cycle of <a href="https://theconversation.com/a-dark-night-is-good-for-your-health-39161">light and dark from the sun is deeply embedded</a> within our evolutionary past as coded in our DNA; we have a “built-in” biological time for body temperature, hormone levels, sleep, and much more, that cycles very close to 24 hours. </p>
<p>Modern society requires synchronization in such things as school start times, work times and television watching times. All of these can desynchronize our social activity from our biological time. There is mounting evidence that <a href="https://royalsocietypublishing.org/doi/full/10.1098/rstb.2014.0120?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%3dpubmed">chronic circadian rhythm disruption</a> leads to several serious diseases as well as depression and mood disorders. On a societal level, the economic impact may also be large.</p>
<h2>Lefties of a boundary healthier than righties?</h2>
<p>As a test of this idea, Giuntella and Mazzonna predicted that at the boundaries between time zones within the United States, people on the left side of the boundary would be healthier than people on the right side, and the economies stronger; the left side would be the eastern extreme of one time zone, and the right side would be the western extreme of the adjacent time zone. The sun sets about an hour later on the right side.</p>
<p>Their primary unit of analysis was the county. They used data from the Centers for Disease Control and Prevention and from the U.S. Census, as well as information on sleep duration and quality from two national surveys. They did several different analyses, one of which was to group counties within 100 miles of the time zone boundary into two groups, one on the left side and one on the right side. They then compared the two groups for health outcomes.</p>
<p>As they predicted, there were discontinuities between counties on either side of time zone boundaries in sleep and in risk of obesity, diabetes, heart disease and breast cancer. In each case, counties on the right side of the boundary did worse: shorter sleep and higher risk of disease. They then calculated an overall composite health index using the diseases cited above, and it, too, was lower in the counties on the right side. They ascribe their findings to the later clock time of sunset on the right side of the boundary.</p>
<p><iframe id="tc-infographic-120" class="tc-infographic" height="400px" src="https://cdn.theconversation.com/infographics/120/12cc5a0adf037d84383fbe28a54dc8a1e726dbac/site/index.html" width="100%" style="border: none" frameborder="0"></iframe></p>
<p>The previous <a href="https://theconversation.com/breast-cancer-risk-higher-in-western-parts-of-time-zones-is-electric-light-to-blame-85803">breast cancer studies</a> from the U.S. and from Russia compared risk within times zones. They found that the western portions were at higher risk.</p>
<p>This new study looks at discontinuities across time zone boundaries. The authors argue that counties close to the time zone border are more similar to one another than counties within the same time zone but at the eastern and western extremes, thus possibly controlling for more confounding factors such as median income, air quality, and other demographic and environmental characteristics. It’s almost 1,000 miles from Nashville to Amarillo, yet only a little more than 100 miles from Nashville to Chattanooga, a city in the same state but a different time zone.</p>
<p>Each of the health outcomes the authors examined has a health care cost associated with it. They estimated a cost of US$2.3 billion per year in the western parts of time zones in the United States. They claim this is a lower estimate of the true cost to society because it was restricted to the working population, or ages 18 to 65, and does not take account of absenteeism and lost productivity due to social jet lag. Nor does it include adverse effects of circadian disruption in children or old people.</p>
<h2>Are we doomed?</h2>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/272894/original/file-20190506-103078-d8xje7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/272894/original/file-20190506-103078-d8xje7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=301&fit=crop&dpr=1 600w, https://images.theconversation.com/files/272894/original/file-20190506-103078-d8xje7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=301&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/272894/original/file-20190506-103078-d8xje7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=301&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/272894/original/file-20190506-103078-d8xje7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=378&fit=crop&dpr=1 754w, https://images.theconversation.com/files/272894/original/file-20190506-103078-d8xje7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=378&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/272894/original/file-20190506-103078-d8xje7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=378&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Before clocks and electricity were invented, humans lived more in sync with the rising and setting of the sun.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/743173996?src=5rz6Sy2Ic4pO5TM4XcZ3UQ-1-53&size=medium_jpg">Mikhail Leonov/Shutterstock.com</a></span>
</figcaption>
</figure>
<p>Before humans invented clocks and began to obey them, people in little groups could eat, sleep and fight anytime they felt like it. </p>
<p>In the mega societies of today, however, there must be some forms of synchronization of human activity; the sun and its shadows are not enough. If we were to abandon clock time now, we would have anarchy.</p>
<p>The problem is that circadian disruption and social jet lag are real and have consequences for our health. The evidence for this comes from many different sources, not just time zone studies.</p>
<p>But there are remedies. We do not have to give up electric light and our modern way of life. The more we learn about circadian disruption, the better we can blunt its impact with better lighting, altered school start times, flexible work hours and the general recognition that <a href="https://theconversation.com/are-we-sleep-deprived-or-just-darkness-deprived-49412">we need both sleep and dark at the appropriate times of the solar cycle</a> for optimum health.</p><img src="https://counter.theconversation.com/content/116630/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Richard G. "Bugs" Stevens does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Humans have natural cycles for when they are active and for when they sleep. Modern work and school schedules interfere with this, and more studies are showing why there’s a possible health risk.Richard G. "Bugs" Stevens, Professor, School of Medicine, University of ConnecticutLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1129382019-03-07T11:39:06Z2019-03-07T11:39:06Z11 things you can do to adjust to losing that 1 hour of sleep when daylight saving time starts<figure><img src="https://images.theconversation.com/files/262539/original/file-20190306-100796-4fr4cz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The loss of even an hour of sleep is hard on the body, and kids are particularly vulnerable.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/asian-child-cute-kid-girl-sleep-1197414388">kornnphoto/Shutterstock.com</a></span></figcaption></figure><p><em>An updated version of this article was published on March 11, 2022. <a href="https://theconversation.com/11-things-you-can-do-to-adjust-to-losing-that-hour-of-sleep-when-daylight-saving-time-starts-179154">Read it here</a>.</em></p>
<p>As clocks march ahead of time on March 10, 2019, and daylight saving time begins, there is a lot of anxiety around losing the hour of sleep and how to adjust to this change.</p>
<p>Usually an hour seems like an insignificant amount of time but considering the global epidemic of our sleep deprived society, even this minimal loss causes many important problems. There are serious health repercussions of this forcible shift in the body clock.</p>
<p>Springing forward is usually harder that falling backward. Why is this so?</p>
<p>People’s natural internal body clock and daily rhythms are slightly longer than 24 hours. So every day, we have a tendency to delay our sleep schedules. Thus, “springing forward” is going against that natural rhythm. It is like a mild case of jet lag caused by traveling east when we lose time and have a hard time falling asleep at an earlier hour.</p>
<p>We co-lead a sleep evaluation center at the University of Pittsburgh Medical Center, Childrens’ Hospital of Pittsburgh and take care of patients with different kinds of sleep disorders. We regularly see patients who are dealing with the effects of sleep loss. We fully understand what’s going on with them because of our in-depth understanding of how the sleep-wake processes work.</p>
<h2>Consequences of sleep loss vary</h2>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/262540/original/file-20190306-100805-1rcfigv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/262540/original/file-20190306-100805-1rcfigv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/262540/original/file-20190306-100805-1rcfigv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/262540/original/file-20190306-100805-1rcfigv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/262540/original/file-20190306-100805-1rcfigv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=504&fit=crop&dpr=1 754w, https://images.theconversation.com/files/262540/original/file-20190306-100805-1rcfigv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=504&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/262540/original/file-20190306-100805-1rcfigv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=504&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Sleep loss from springing forward has been associated not only with sleepiness at work but also an increase in work accidents.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/portrait-young-woman-sitting-table-front-472129438">fizkes/Shutterstock.com</a></span>
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<p>Many studies have now demonstrated that there is an increased risk <a href="https://www.acc.org/about-acc/press-releases/2014/03/29/09/16/sandhu-daylight-saving">of heart attacks</a>, stroke and high blood pressure associated with sleep deprivation. <a href="https://www.oshasafetymanagement.com/blog/dont-let-workplace-injuries-spring-ahead-in-coming-days/">Workplace injuries</a> increase and so do <a href="https://www.ncbi.nlm.nih.gov/pubmed/11152980">automobile accidents</a>. Adolescents, of course, find it harder to wake up in time to get to school.</p>
<p>Is there something we can do to deal with this loss of sleep and change of body clock timing?</p>
<p>Of course. The first step to dealing with this is increasing awareness and using the power of knowledge to combat this issue. Here are some quick tips to prepare yourself for the upcoming weekend.</p>
<ol>
<li><p>Do not start with a “sleep debt.” Ensure that you and your child get adequate sleep on a regular basis in the weeks leading up to the time change each year. Most adults need anywhere from seven to nine hours of sleep daily to perform adequately. Children have <a href="https://www.aap.org/en-us/about-the-aap/aap-press-room/pages/American-Academy-of-Pediatrics-Supports-Childhood-Sleep-Guidelines.aspx">varying requirements for sleep depending on their age</a>.</p></li>
<li><p>Prepare for the time change. Start going to bed or putting your kids to bed 15 to 20 minutes earlier each night in the week preceding the time change. Also, move your wake timing during the week as this will help you fall asleep earlier. Aim for waking up an hour earlier on the Saturday before the time change.</p></li>
<li><p>Use light to your advantage. Light is the strongest cue that helps adjusts our internal body clock. When possible, expose yourself to bright light early in the morning upon awakening. If you live somewhere where natural light may be limited in the morning after clocks change, use artificial bright lights to signal to your body clock to wake up earlier. As the season progresses, this will be less of an issue as the sun rises earlier in the day. Conversely, at night, minimize exposure to bright light, especially the blue light emitting from screens of electronic media. Turn off electronics even earlier than the usual recommended duration of one to two hours before bedtime. In some places, it might be helpful to have room-darkening curtains in the bedroom depending on how much sunlight that room gets at bedtime.</p></li>
<li><p>Carefully plan your day and evening activities. Start planning your day the night before the time change with a good night’s sleep.</p></li>
<li><p>Incorporate exercise in the morning and leave relaxing activities for the evening. This may help you to wind down. Take a walk even if it is just around the house or your office.</p></li>
<li><p>Set an alarm for an earlier bedtime and earlier electronics turn-off time.</p></li>
<li><p>Start with a protein-heavy breakfast, as sleep deprivation can increase appetite and craving for high-carbohydrate foods and sugars.</p></li>
<li><p>Stop using caffeine after noon.</p></li>
<li><p>Adults, decline that wine at bedtime.</p></li>
<li><p>Try to be patient with your kids as they adjust to the new times. We all know that sleep deprivation impacts the entire family. Children are just as confused about this change as adults. Some kids have a harder time adjusting than others. You may notice more frequent meltdowns, irritability, loss of attention and focus. Set aside more quiet electronic-media-free time in the evening or maybe a 20-minute nap in the early afternoon while they deal with this change.</p></li>
<li><p>Use electronics judiciously. Television, smartphones, tablets and video games are some of the perils of the world we live in. While there are benefits of this technology, especially in helping people stay connected, it can be disruptive at bedtime and in the bedroom. The blue light emitted from these devices signals our internal clock to wake up later the next day and shifts our body rhythm. It is a modern-day challenge that we have to constantly deal with preserving our natural sleep wake rhythm and our health.</p></li>
</ol>
<p>As the National Sleep Foundation celebrates its annual <a href="https://www.sleepfoundation.org/press-release/sleep-awareness-week-2019">Sleep Awareness Week</a> March 10 to 16, let’s pledge to uphold its theme to “Begin with Sleep” when planning for our day. A good night’s sleep is the recipe for a productive and fulfilling day.</p>
<p><em>This is an updated version of an article originally published on March 7, 2019.</em></p><img src="https://counter.theconversation.com/content/112938/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Deepa Burman is affiliated with American Board of Internal Medicine as a member of the Sleep Medicine Board Exam Test Question Writing Committee. </span></em></p><p class="fine-print"><em><span>Hiren Muzumdar does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Springing forward onto daylight saving time means Americans will lose an hour of sleep. Two sleep doctors offer some survival tips as you adjust.Deepa Burman, Co-Director Pediatric Sleep Evaluation Center and Associate Professor of Pediatrics, University of PittsburghHiren Muzumdar, Director of the Pediatric Sleep Evaluation Center, UPMC Children’s Hospital of Pittsburgh, University of PittsburghLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1115062019-03-04T11:38:29Z2019-03-04T11:38:29Z5 ways life would be better if it were always daylight saving time<figure><img src="https://images.theconversation.com/files/260527/original/file-20190223-195876-m326tq.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5826%2C3998&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Never "spring forward" or "fall back" again.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/sleepy-woman-reaching-holding-alarm-clock-1278539797?src=aVrUsNUlqZqX-Ln5zM00WQ-1-13">Pair Srinrat/Shutterstock.com</a></span></figcaption></figure><p>In <a href="http://wakeforestlawreview.com/2008/01/time-well-spent-an-economic-analysis-of-daylight-saving-time-legislation/">my research</a> on daylight saving time, I have found that Americans don’t like it when Congress messes with their clocks. </p>
<p>In an effort to avoid the biannual clock switch in spring and fall, some well-intended critics of DST have made the mistake of suggesting that the abolition of DST – and a return to permanent standard time – would benefit society. In other words, the U.S. would never “spring forward” or “fall back.”</p>
<p>They are wrong. DST saves lives and energy and prevents crime. Not surprisingly, then, politicians <a href="https://www.seattlepi.com/news/politics/article/Washington-passed-a-law-to-stay-on-DST-forever-14803071.php">in Washington</a> and <a href="https://www.orlandosentinel.com/news/politics/political-pulse/os-daylight-saving-law-20180703-story.html">Florida</a> have passed laws aimed at moving their states to DST year-round.</p>
<p>Congress should seize on this momentum to move the entire country to year-round DST. In other words, turn all clocks forward permanently. If it did so, I see five ways that Americans’ lives would immediately improve.</p>
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<h2>1. Lives would be saved</h2>
<p>Simply put, darkness kills – and darkness in the evening is far deadlier than darkness in the morning. </p>
<p>The evening rush hour is twice as fatal as the morning for various reasons: <a href="https://dx.doi.org/10.1136%2Fip.2005.011056">Far more people are on the road</a>, more alcohol is in drivers’ bloodstreams, people are hurrying to get home and more children are enjoying <a href="http://commdocs.house.gov/committees/science/hsy73325.000/hsy73325_0.HTM">outdoor, unsupervised play</a>. Fatal vehicle-on-pedestrian crashes <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1615292/">increase threefold</a> when the sun goes down.</p>
<p>DST brings an extra hour of sunlight into the evening to mitigate those risks. Standard time has precisely the opposite impact, by moving sunlight into the morning. </p>
<p>A meta-study by Rutgers researchers demonstrated that <a href="https://www.ncbi.nlm.nih.gov/pubmed/15003579">343 lives per year</a> could be saved by moving to year-round DST. The opposite effect would occur if the U.S. imposed year-round standard time.</p>
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<h2>2. Crime would decrease</h2>
<p>Darkness is also a friend of crime. Moving sunlight into the evening hours has a far greater impact on the prevention of crime than it does in the morning. This is especially true for <a href="https://www.ojjdp.gov/ojstatbb/offenders/qa03401.asp?qaDate=2016">crimes by juveniles</a>, which peak in the after-school and early evening hours.</p>
<p>Criminals strongly prefer to do their work in the darkness of evening and night. <a href="https://doi.org/10.1016/S0169-2070(03)00093-1">Crime rates are lower</a> by 30 percent in the morning to afternoon hours, even when those morning hours occur before sunrise, when it’s still dark.</p>
<p>A 2013 British study found that improved lighting in the evening hours could <a href="http://library.college.police.uk/docs/what-works/What-works-briefing-improved-street-lighting-2013.pdf">reduce the crime rate by up to 20 percent</a>. </p>
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<h2>3. Energy would be saved</h2>
<p>Many people don’t know that the <a href="http://wakeforestlawreview.com/2008/01/time-well-spent-an-economic-analysis-of-daylight-saving-time-legislation/">original justification for the creation of DST</a> was to save energy, initially during World War I and II and then later during the 1973 OPEC oil crisis. When the sun is out later in the evening, peak energy loads are reduced.</p>
<p>Virtually everyone in our society is awake and using energy in the early evening hours when the sun sets. But a considerable portion of the population is still asleep at sunrise, resulting in significantly less demand for energy then. </p>
<p>Having more sun in the evening requires not just less electricity to provide lighting, but <a href="https://www.energy.ca.gov/reports/2001-05-23_400-01-013.PDF">reduces the amount of oil and gas required to heat homes and businesses</a> when people need that energy most. Under standard time, the sun rises earlier, reducing morning energy consumption, but only half of Americans are awake to be able to use the sun.</p>
<p>This rationale motivated some in California to recommend permanent DST a decade ago, when the state experienced recurrent electricity shortages and rolling brown-outs. Officials at the California Energy Commission estimated that <a href="https://www.energy.ca.gov/reports/2001-05-23_400-01-013.PDF">3.4 percent of California’s winter energy usage</a> could be saved by moving to year-round DST. </p>
<p>Similarly, DST resulted in 150,000 barrels of oil saved by the U.S. in 1973, which helped combat the effect of OPEC’s oil embargo.</p>
<h2>4. Avoiding clock switches improves sleep</h2>
<p>Critics of DST are correct about one thing: The biannual clock switch is bad for health and welfare. </p>
<p>It wreaks havoc with people’s sleep cycles. Heart attacks <a href="https://healthblog.uofmhealth.org/heart-health/why-daylight-saving-time-could-increase-your-heart-attack-risk">increase 24 percent</a> in the week after the U.S. “springs forward” in March. There’s even an uptick during the week in November when the clocks “fall back.” </p>
<p>If that’s not bad enough, a study from 2000 shows that the major financial market indexes NYSE, AMEX and NASDAQ <a href="https://www.jstor.org/stable/117321?seq=1#metadata_info_tab_contents">average negative returns</a> on the Monday trading day following both clock switches, presumably because of disrupted sleep cycles.</p>
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<p>Critics of biannual clock switching sometimes use these points to argue in favor of permanent standard time. However, I think it’s important to note that these same sleep benefits are available under year-round DST, too. Plus, standard time doesn’t offer the energy or lifesaving or crime prevention effects of DST. </p>
<h2>5. Recreation and commerce flourish in the sun</h2>
<p>Finally, recreation and commerce flourish in daylight and are hampered by evening darkness. </p>
<p>Americans are <a href="https://qz.com/1120488/daylight-saving-time-as-americans-know-it-was-instituted-by-corporate-lobbies-not-farmers/">less willing to go out and shop in the dark</a>, and it’s not very easy to catch a baseball in darkness either. These activities are far more prevalent in the early evening than they are in the early morning hours, so sunlight is not nearly as helpful then. </p>
<p>Not surprisingly, the U.S. Chamber of Commerce as well as most outdoor recreational interests <a href="https://www.washingtonpost.com/opinions/five-myths-about-daylight-saving-time/2015/03/06/970092d4-c2c1-11e4-9271-610273846239_story.html?utm_term=.d446e4c4cf34">favors extended DST</a>.</p>
<p>Research shows that sunlight is far more important to Americans’ health, efficiency and safety in the early evening than it is in the early morning. That’s not to say there aren’t downsides to DST – notably, an extra hour of morning darkness. But I believe the advantages of extended DST far outweigh those of standard time. It is past time that the U.S. sets the clocks forward forever, and never has to switch them again.</p>
<p><em>This is an updated version of a story that was originally published on March 4, 2019.</em></p><img src="https://counter.theconversation.com/content/111506/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Steve Calandrillo does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Washington, California and Florida are mulling a permanent switch to DST. Proponents say that doing so could improve health, save energy and prevent crime.Steve Calandrillo, Jeffrey & Susan Brotman Professor of Law, University of WashingtonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1062432018-11-03T16:29:57Z2018-11-03T16:29:57ZHere’s what happens the day after the clocks change<figure><img src="https://images.theconversation.com/files/299965/original/file-20191103-88378-5dra3g.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C4476%2C2351&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The twice-annual time changes affect people similar to the way jet lag does. It's time to abolish daylight-saving time. </span> <span class="attribution"><span class="source">Andrew Seaman/Unsplash</span></span></figcaption></figure><p>Society has a love/hate relationship with daylight-saving time changes.</p>
<p>At this time of year, many of us delight in the extra hour of sleep that comes with turning the clocks back. However, when spring rolls around, we invariably curse the loss of sleep that accompanies setting the clocks forward.</p>
<p>The decadence of extra snooze time aside, disruptions in sleep can wreak havoc on our minds and bodies. Deviations from our normal sleep habits, known as <a href="https://www.ncbi.nlm.nih.gov/pubmed/6151390">sleep desynchronosis</a>, can lead to the same sorts of symptoms that arise from jet lag, including reduced attention span, judgment errors and anxiety. </p>
<p>Worse, the evidence shows time changes are associated with an increase in the numbers of <a href="https://www.nejm.org/doi/full/10.1056/NEJM199810153391617">car accidents</a> and <a href="https://www.nejm.org/doi/full/10.1056/NEJMc0807104">heart attacks</a>.</p>
<h2>Sleepy stock markets</h2>
<p>The time changes also have adverse consequences for financial markets. Research I conducted with Mark Kamstra of York University and Maurice Levi of the University of British Columbia found that stock markets tend to draw back significantly on the Monday after a time change, whether the clocks lose or gain an hour.</p>
<p><a href="https://www.aeaweb.org/articles?id=10.1257/000282803321455322">We studied</a> stock market returns in several countries, some of which implemented time changes on different dates than others, and we found that after controlling for other factors that influence markets, there was a significant drop following the time change. </p>
<p>Of course, what happens on any given day is a combination of many factors, including fundamental news about various companies and the overall economy. And yet we found a statistically significant negative average stock return that was much greater in magnitude than the negative return that typically arises on Mondays. (Other days of the week tend to have positive returns.) </p>
<p>We calculated that, in the United States alone, the average one-day loss on stock markets due to a daylight-saving time change amounted to more than US$30 billion. </p>
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<img alt="" src="https://images.theconversation.com/files/243749/original/file-20181103-83657-lziftu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/243749/original/file-20181103-83657-lziftu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=187&fit=crop&dpr=1 600w, https://images.theconversation.com/files/243749/original/file-20181103-83657-lziftu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=187&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/243749/original/file-20181103-83657-lziftu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=187&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/243749/original/file-20181103-83657-lziftu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=235&fit=crop&dpr=1 754w, https://images.theconversation.com/files/243749/original/file-20181103-83657-lziftu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=235&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/243749/original/file-20181103-83657-lziftu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=235&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">When the clocks spring forward or fall back, it causes problems for human health and the economy.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
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<p>We surmise that these twice-a-year losses arose as a consequence of investors being more anxious after a sleep disruption and hence more reluctant to buy or to continue holding risky assets than they would be in absence of the shock to their routine. </p>
<p>This stock market example is part of a much larger phenomenon whereby the biological effects of sleep changes have negative implications across the wider economy. </p>
<p><a href="http://psycnet.apa.org/doiLanding?doi=10.1037%2Fa0015320">Workplace accidents tend to be greater</a> in both frequency and severity following daylight-saving time changes, which translates into lost wages, higher worker’s compensation costs, higher medical costs, more training costs for replacement workers and reduced productivity overall. On balance, the time changes are expensive for both business and government.</p>
<h2>Year-round daylight-saving time</h2>
<p>Of course it’s not necessary for a region to adopt standard time in the event that time changes were abolished. </p>
<p>The other obvious alternative is to remain on daylight-saving time year-round — meaning, essentially, that the clocks don’t change twice a year. That option that would arguably lead to relatively better outcomes in terms of financial markets, car accidents, heart attacks and workplace injuries. </p>
<p>Year-round daylight saving time has additional likely advantages. The state of Massachusetts evaluated the relevant academic literature <a href="http://www.eileendonoghue.org/media/The-Report-of-the-Special-Commission-on-the-Commonwealth%E2%80%99s-Time-Zone.pdf">and concluded</a> that reduced street crime would result from remaining on daylight-saving time permanently, including a reduction in robberies due to more daylight in the evening hours and possibly a decrease in the incidence of rape.</p>
<p>When daylight-saving time changes were first being adopted in various jurisdictions more than a century ago, energy cost savings were touted as a major benefit. The details depend on the specific latitude and time zone, but it now appears that these benefits were vastly overstated.</p>
<p><a href="https://www.mitpressjournals.org/doi/abs/10.1162/REST_a_00131">Recent studies</a> have found that adopting daylight-saving time year-round would lead to modest energy savings and perhaps reduced greenhouse gas emissions too.</p>
<p>The implications of year-round daylight-saving time wouldn’t all be sunny, however. An undesirable implication would be darkness during the morning period when children often head to school. For some locations, this may suggest a need to shift school start times later so there is daylight when students are on their morning trek to classes. </p>
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<img alt="" src="https://images.theconversation.com/files/243751/original/file-20181103-83635-1p3efa2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/243751/original/file-20181103-83635-1p3efa2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/243751/original/file-20181103-83635-1p3efa2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/243751/original/file-20181103-83635-1p3efa2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/243751/original/file-20181103-83635-1p3efa2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/243751/original/file-20181103-83635-1p3efa2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/243751/original/file-20181103-83635-1p3efa2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Ending daylight saving time changes will mean children will need to start school later. Businesses will therefore need to accommodate parents.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
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<p>That would also require work hours to change for parents of younger, school-aged children. They’d have to start later in order to get their kids to school.</p>
<p>But this inconvenience is worth bearing, since <a href="http://pediatrics.aappublications.org/content/134/3/642">child development experts maintain</a> that later school start times are better for kids’ attendance and learning outcomes anyway. </p>
<h2>Clocks may soon stop shifting</h2>
<p>European citizens recently participated in public consultation about daylight-saving time changes, and the <a href="https://www.theguardian.com/world/2018/aug/31/eu-recommend-member-states-abolish-daylight-saving-time">majority of respondents expressed a desire to adopt daylight-saving time year round</a>. </p>
<p>Accordingly, the European Council has recommended that member countries stop adjusting the clocks twice a year and instead remain perpetually “sprung forward.” The matter is working its way through the legislative process. </p>
<p>If adopted by the European Parliament, adherence to this recommendation would be voluntary on the part of individual European nations. But for the first time in decades, the real possibility exists that some major world economies will stop shifting their clocks.</p>
<p>Overall, the time has arrived for us to stop losing sleep over the twice-yearly time changes and to stick with daylight-saving time all year long. May the shift to year-round daylight-saving time everywhere come swiftly, for the good of our health and the economy.</p><img src="https://counter.theconversation.com/content/106243/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Lisa Kramer receives funding from the Social Sciences and Humanities Research Council of Canada. </span></em></p>Research shows that daylight-saving time changes do more harm than good. It’s time to abolish the practice.Lisa Kramer, Professor of Finance, University of TorontoLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/936462018-10-05T06:59:16Z2018-10-05T06:59:16ZHow the switchover to daylight saving time affects our health<figure><img src="https://images.theconversation.com/files/239438/original/file-20181005-52666-emng91.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Changing to daylight saving time can impact our mood, our risk of heart attack and how much exercise we get.</span> <span class="attribution"><a class="source" href="https://unsplash.com/photos/rUc9hVE-L-E">Gregory Pappas</a></span></figcaption></figure><p>On Saturday night, Australians who switch over to daylight saving time will get an hour less of sleep as they move their clocks forward. </p>
<p>Changing the clock causes a temporary state of misalignment in our internal biological time. We may not feel ready to go to bed an hour earlier and our alarms will wake us up before we’ve had enough sleep. </p>
<p>Changing the clock alters the body’s rhythmic production of melatonin, the hormone produced when it gets dark, and cortisol, the stress hormone. These regulate when we feel like going to sleep, when we’re hungry, and our ability to fight off bugs. </p>
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Read more:
<a href="https://theconversation.com/health-check-what-determines-whether-were-night-owls-or-morning-larks-64437">Health Check: what determines whether we're night owls or morning larks?</a>
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<p>This misalignment is a form of jetlag, and can upset the body’s rhythms. It can affect our ability to think clearly and can increase the risk of heart attacks, <a href="https://www.ncbi.nlm.nih.gov/pubmed/27775953">depression</a>, and even miscarriage. </p>
<h2>Heart attack and stroke</h2>
<p>Several studies have shown <a href="https://www.ncbi.nlm.nih.gov/pubmed/18971502">your risk of having a heart attack</a> (myocardial infarction) and <a href="https://www.ncbi.nlm.nih.gov/pubmed/27938913">stroke</a> increases in the two weeks after the changeover, compared with the two weeks before. The <a href="http://www.nejm.org/doi/full/10.1056/NEJMc0807104">risk is highest</a> in the first three weekdays following the switchover. </p>
<p>Researchers suspect the link is because an hour of sleep loss increases stress and provides less time to recover overnight.</p>
<p>The good news is the increased risk of a heart attack only appears to last for two weeks. After that, our biological clock seems to synchronise to the new time (though <a href="https://www.ncbi.nlm.nih.gov/m/pubmed/17964164/">researchers are divided</a> on this).</p>
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<img alt="" src="https://images.theconversation.com/files/212575/original/file-20180329-189804-18ji6ng.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/212575/original/file-20180329-189804-18ji6ng.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/212575/original/file-20180329-189804-18ji6ng.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/212575/original/file-20180329-189804-18ji6ng.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/212575/original/file-20180329-189804-18ji6ng.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/212575/original/file-20180329-189804-18ji6ng.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/212575/original/file-20180329-189804-18ji6ng.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">A person’s risk of heart attack may increase after the transition to and from daylight saving time.</span>
<span class="attribution"><span class="source">from shutterstock.com</span></span>
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<p>When it comes to the increased risk of heart attack, <a href="https://www.ncbi.nlm.nih.gov/pubmed/18971502">women are generally more sensitive</a> to the spring transition <em>to</em> daylight saving time, while men are more sensitive to the autumn transition <em>from</em> daylight saving time. </p>
<p>The reasons are unclear but it could be related to the roles sex-specific hormones play in the adjustment.</p>
<h2>Mood</h2>
<p><a href="https://ideas.repec.org/a/spr/jhappi/v17y2016i6d10.1007_s10902-015-9695-8.html">Research from Germany</a> shows springing forward to summertime can have a negative effect on life satisfaction levels and feelings of anger and sadness, which can last a little over a week. </p>
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Read more:
<a href="https://theconversation.com/daylight-saving-is-not-something-for-economists-to-lose-sleep-over-103316">Daylight saving is not something for economists to lose sleep over</a>
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<p>The effect is largest among full-time employees. These workers must instantaneously shift their work schedule to a time that’s in disagreement with their body’s biological rhythms, while others may allow themselves to ease into their new schedule. </p>
<p>Your risk of depression can also increase during the month after the daylight saving comes into effect. A 17-year <a href="https://insights.ovid.com/crossref?an=00001648-201705000-00007">Danish study</a> of 185,419 hospital visits found the patient intake for patients diagnosed with depression rose by 11%. This effect dissipated over a ten-week period. </p>
<h2>Miscarriage</h2>
<p>A <a href="https://www.tandfonline.com/doi/abs/10.1080/07420528.2017.1279173?journalCode=icbi20">2017 study</a> of IVF patients found a greater chance of pregnancy loss after embryo transfer in spring, when daylight saving time began: 24.3%, as opposed to 15.5% before daylight saving time. </p>
<p>There was no significant difference in pregnancy loss rates during the transition <em>from</em> daylight saving time.</p>
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<img alt="" src="https://images.theconversation.com/files/212573/original/file-20180329-189804-1iiar4w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/212573/original/file-20180329-189804-1iiar4w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/212573/original/file-20180329-189804-1iiar4w.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/212573/original/file-20180329-189804-1iiar4w.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/212573/original/file-20180329-189804-1iiar4w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/212573/original/file-20180329-189804-1iiar4w.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/212573/original/file-20180329-189804-1iiar4w.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Researchers have found a link between daylight saving time and IVF pregnancy loss.</span>
<span class="attribution"><span class="source">William Stitt/unsplash</span></span>
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<h2>Physical activity</h2>
<p>The transition to daylight saving time affects people’s exercise patterns. A <a href="https://www.ncbi.nlm.nih.gov/pubmed/20920111">2010 Australian study</a> found one in four people switched from morning to evening exercise sessions. But 8% stopped exercising altogether after the changeover. </p>
<p>However, a <a href="https://ijbnpa.biomedcentral.com/articles/10.1186/1479-5868-11-84">much larger study of Australian children</a> found that daylight saving time increases children’s physical activity in the afternoon and evenings, by around two minutes per day. </p>
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Read more:
<a href="https://theconversation.com/start-resetting-your-kids-body-clocks-before-daylight-saving-ends-heres-how-93792">Start resetting your kids' body clocks before daylight saving ends – here's how</a>
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<h2>Night owl or morning lark?</h2>
<p>The effect of daylight saving time depends on <a href="https://www.ncbi.nlm.nih.gov/pubmed/24679223">our chronotype</a>: whether you’re a night owl or early rising lark. </p>
<p>We switch chronotypes as we age; adolescents are <a href="https://www.ncbi.nlm.nih.gov/pubmed/19346161">predominantly night owls</a> but many will eventually switch to being morning larks in adulthood. So the impact of the transition to daylight saving time also changes as we age.</p>
<p>A <a href="https://www.ncbi.nlm.nih.gov/pubmed/19346161">2009 German study</a> showed that daytime sleepiness was an issue for older students for up to three weeks after the transition to daylight saving time. This is why sleep experts urge schools not to test students in the three weeks after the transition. </p>
<p>We all need time to adjust to daylight saving time – but students and full-time workers might have a tougher time in the weeks after the changeover. So go easy on your kids and colleagues.</p><img src="https://counter.theconversation.com/content/93646/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Oliver Rawashdeh does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Daylight saving time begins this weekend, which means many of us will get an hour less sleep. But the health effects go beyond sleep – and can last two weeks or more. Here’s what the research says.Oliver Rawashdeh, Lecturer in Biomedical Sciences, The University of QueenslandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1033162018-10-04T20:06:32Z2018-10-04T20:06:32ZDaylight saving is not something for economists to lose sleep over<figure><img src="https://images.theconversation.com/files/239241/original/file-20181003-52672-ifoi2c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Waking an hour earlier on Monday won't make you much more dangerous.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/">Shutterstock</a></span></figcaption></figure><p>Have you ever noticed that casinos don’t have clocks or windows? </p>
<p>That’s partly to encourage customers to lose track of time. Their owners have instinctively understood – long before this recent <a href="http://www.jneurosci.org/content/31/10/3712.long">neuroscience study</a> confirmed it – that sleep-deprived people tend to take more risks.</p>
<p>We have a wealth of knowledge from laboratory studies about what sleep loss does to mood, behaviour and our ability to think and work.</p>
<p>We get a taste of it when we travel across time zones, work night shifts or pull all-nighters before exams. </p>
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Read more:
<a href="https://theconversation.com/daylight-saving-why-changing-sas-clocks-could-make-us-sleepy-and-accident-prone-46260">Daylight saving: why changing SA's clocks could make us sleepy and accident-prone</a>
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<p>But what do we know about the real-life effects of the one hour of sleep loss that most of us experience on the same weekend each year due to daylight saving?</p>
<h2>Spring forward</h2>
<p>On the first Sunday of October, at 2am, clocks in NSW, Victoria, Tasmania, South Australia and the Australian Capital Territory spring forward an hour. People in those states are forced to get up earlier than they are used to.</p>
<p>Our cycle of sleep and waking is called our circadian rhythm – from the Latin <em>circa</em> (about) and <em>dies</em> (day). It is controlled by a tiny region in the hypothalamus of our brains that also regulates our hormone production, digestive function, electrolyte levels, body temperature and resting heart rate.</p>
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Read more:
<a href="https://theconversation.com/100-years-later-the-madness-of-daylight-saving-time-endures-93048">100 years later, the madness of daylight saving time endures</a>
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<p>Jumping forward an hour means that, to start with, these things happen when we don’t want them to. It’s a bit like mild jet lag. Jumping forward at the beginning of daylight saving is worse than slipping back at the end, because it also eats into our sleep.</p>
<h2>More risks</h2>
<p>Many <a href="https://www.aeaweb.org/articles?id=10.1257/aer.90.4.1005">experts</a> attribute accidents (such as the crash of American Airlines Flight 1420, the explosions of the space shuttle Challenger and the Chernobyl nuclear power plant, and the Exxon Valdez oil spill) to human error caused by lost sleep.</p>
<p>It can also affect our normal approach to “economic risks”. </p>
<p>A “daylight saving anomaly” has been described in international financial markets. <a href="https://www.researchgate.net/publication/4726577_Losing_Sleep_at_the_Market_The_Daylight_Saving_Anomaly">According to a well-known study</a> published in 2000, stock market returns were negatively affected in the weeks after both the change to and from daylight saving time. “In the United States alone,” they concluded, “the daylight saving effect implies a one-day loss of $31 billion on the NYSE, AMEX and NASDAQ indexes.”</p>
<p>The <a href="http://www.jneurosci.org/content/31/10/3712.long">neuroscience study</a> mentioned above provides the first solid evidence that sleep deprivation makes gambling more tempting. This supports a previous finding that people with disturbed sleep are <a href="https://www.ncbi.nlm.nih.gov/pubmed/22356670">more likely to be problem gamblers</a>. </p>
<p><a href="https://www.ncbi.nlm.nih.gov/pubmed/17716272">Another study</a> finds that sleep deprivation accentuates the tendency to take risks in pursuit of potential gains but to be even more risk-averse when faced with potential losses. </p>
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Read more:
<a href="https://theconversation.com/the-dark-side-of-daylight-saving-time-91958">The dark side of daylight saving time</a>
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<p>The results from the laboratory studies are usually hard to generalise to real-life situations. </p>
<p>The annual move to daylight saving in some states but not in others provides a real-world opportunity to examine if missing an hour’s sleep by bringing the clock forward an hour makes a practical difference to ordinary people going about their lives. </p>
<h2>Not in Australia</h2>
<p>I and colleagues Markus Schaffner, Benno Torgler and Uwe Dulleck recruited volunteers from both sides of the Queensland-NSW border. All lived within a short distance of each other. None were told to lose sleep.</p>
<p>The only known difference between those on each side of the border (except for their State of Origin jersey colours) was that those in NSW had their rhythms disrupted by the start of daylight saving.</p>
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Read more:
<a href="https://theconversation.com/is-daylight-saving-time-worth-the-trouble-research-says-no-86739">Is daylight saving time worth the trouble? Research says no</a>
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<p>A week before the switch we had participants do two tests. The first required them to call mismatches between the name of a colour (i.e. “RED”) and the colour the word was displayed in. The second asked them to choose between different types of lotteries offering small amounts of cash as prizes.</p>
<p>We did it again immediately after the switch to daylight saving, and again a week later.</p>
<p>We found <a href="https://www.sciencedirect.com/science/article/pii/S0264999317312294">no statistical difference</a> in cognitive performance or risk-taking behaviour, either on the day of the switch or one week after.</p>
<p>The results suggest that, away from the laboratory, the lost hour of sleep and the changed displays on our clocks don’t affect us much.</p>
<h2>Fingers poised</h2>
<p>It doesn’t mean bigger sleep disruptions don’t make a difference.</p>
<p>Many heads of states appear to be sleep-deprived. US president Donald Trump says he sleeps just <a href="https://www.businessinsider.com.au/some-people-only-need-a-few-hours-of-sleep-2016-12?r=US&IR=T">four to five hours a night</a>. </p>
<p>He has his finger on the world’s biggest nuclear button. Should that alarm us? I’ll leave that to you.</p>
<p>Drive safely on Monday.</p><img src="https://counter.theconversation.com/content/103316/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jayanta Sarkar does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Overseas research says putting the clock forward hurts the financial markets. But not in Australia, according to a real-world study along the Queensland-NSW border.Jayanta Sarkar, Senior Lecturer, Economics and Finance, Queensland University of TechnologyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/949522018-04-17T10:43:00Z2018-04-17T10:43:00ZLight at night can disrupt circadian rhythms in children – are there long-term risks?<figure><img src="https://images.theconversation.com/files/214832/original/file-20180413-540-1a6oi6i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Could too much light in the evening affect children's sleep? Recent research suggests that it could.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/sweet-little-girl-asleep-her-bed-121356385?src=xNY9DJGugwRUYT9TbC-pow-1-30">Giideon/Shutterstock.com</a></span></figcaption></figure><p>A new scientific study shows that bright electric light exposure of preschool children in the evening suppresses <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5835497/">melatonin production almost completely</a>, an important addition to the growing body of research in this area. Melatonin suppression is a marker of <a href="https://theconversation.com/a-dark-night-is-good-for-your-health-39161">disruption of our circadian rhythms</a>.</p>
<p>Ten kids, ages 3 to 5, were exposed to bright light (~1000 <a href="https://www.noao.edu/education/QLTkit/ACTIVITY_Documents/Safety/LightLevels_outdoor+indoor.pdf">lux</a> from a light box) for one hour before their habitual bedtime, about 8 p.m. Melatonin suppression (where the body stops producing this hormone) began within 10 minutes and continued for another hour after the bright light was turned off at 8 p.m., which was well into their usual sleep period. <a href="https://sleepfoundation.org/sleep-topics/melatonin-and-sleep">Melatonin is a hormone</a> that is important for healthy circadian rhythms and good sleep. </p>
<p>This could undoubtedly reduce <a href="https://www.washingtonpost.com/posteverything/wp/2015/10/27/we-dont-need-more-sleep-we-just-need-more-darkness/?utm_term=.cf74c9001415">sleep quality</a>, but may also cause other serious problems in the longer term.</p>
<h2>When seeing the light can be bad</h2>
<p>The new study built upon a <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4702443/">2015 study of children and adolescents</a> ages 9 to 16. It reported greater sensitivity to light exposure in the younger children compared to the older. That study used several different evening light levels in a laboratory setting that ranged from dim (~15 lux), to moderate (~150 lux, like a 60W incandescent lamp bulb), to bright (~500 lux) and showed a dose response; the dim light suppressed melatonin about 9 percent; moderate light about 26 percent; and bright light about 37 percent in the younger children, less so in the older kids. </p>
<p>Although the researchers used fluorescent room lights in their study, the authors make a point of suggesting that since smartphone use is <a href="http://pediatrics.aappublications.org/content/140/Supplement_2/S92.long">now common in children</a>, even preschoolers, the circadian effects from their use could be considerable because they expose children to bright light close to the face.</p>
<p>There are at least three reasons that too much light during the evening could matter to the health of children, and all are terrible: depression, suicide and cancer. </p>
<p>Excess evening electric light is part of what I call “light pollution,” which is defined as “pollution of night by electric light, whether inside at home or outside in the neighborhood and city.” It is a rapidly <a href="https://www.sciencealert.com/new-atlas-shows-extent-of-light-pollution-what-does-it-mean-for-our-health">growing problem in the modern world</a>.</p>
<h2>Light pollution at its most intimate – the smartphone</h2>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/214836/original/file-20180413-584-1fn7q9b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/214836/original/file-20180413-584-1fn7q9b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/214836/original/file-20180413-584-1fn7q9b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/214836/original/file-20180413-584-1fn7q9b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/214836/original/file-20180413-584-1fn7q9b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/214836/original/file-20180413-584-1fn7q9b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/214836/original/file-20180413-584-1fn7q9b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A girl with a smartphone at bedtime. Research suggests that the lights from smartphones could be disrupting circadian rhythms.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/little-girl-smartphone-lying-bed-bedtime-418297288?src=hbTypcNW1M8ZV3YMXFx6nQ-1-17">Halfpoint/Shutterstock.com</a></span>
</figcaption>
</figure>
<p>A common response to <a href="https://caps.ucsc.edu/resources/depression.html">severe depression is suicide</a>. Well over 40,000 Americans <a href="https://afsp.org/about-suicide/suicide-statistics/">die by suicide each year</a>, more than from <a href="https://www.asirt.org/safe-travel/road-safety-facts/">automobile crashes</a> and close to the <a href="https://www.cancer.org/cancer/colon-rectal-cancer/about/key-statistics.html">number of deaths from colon cancer</a>. In addition, nearly a half million are hospitalized for self-harm, many of whom were injured in their failed attempt at suicide. </p>
<p>This is especially tragic when it happens to the very young.</p>
<p><a href="http://www.jeantwenge.com">Jean Twenge</a> studies mental health and social adjustment in young people, particularly those born after 1995. Her research has focused on smartphones, as described in several informative and provocative recent <a href="https://theconversation.com/with-teen-mental-health-deteriorating-over-five-years-theres-a-likely-culprit-86996">articles published by The Conversation</a>. The articles are based on her own studies published in peer-reviewed scientific journals.</p>
<p>Twenge has found links between “new media” screen time (e.g., smartphones) and risk of depression and suicide in teenagers based on <a href="http://www.monitoringthefuture.org/">two large samples</a> of <a href="https://www.cdc.gov/healthyyouth/data/yrbs/index.htm">young people</a> in the U.S.</p>
<p>Twenge proposes as possible causes for her findings social isolation, sleep deprivation, or both. In <a href="http://www.sleep-journal.com/article/S1389-9457(17)30350-7/fulltext">another recent analysis</a>, Twenge focused on sleep duration and concluded that “increased new media screen time may be involved in the recent increases (from 35 percent to 41 percent and from 37 percent to 43 percent) in short sleep among adolescents.”</p>
<p>Circadian disruption could be the underlying culprit. Bright light in the evening <a href="https://theconversation.com/a-dark-night-is-good-for-your-health-39161">delays transition to nighttime physiology,</a> which should begin at dusk. It thereby <a href="http://www.pnas.org/content/112/4/1232.long">degrades sleep quality</a>. </p>
<p>There is also evidence that circadian disruption can cause depression and other <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4490783/">adverse mood changes</a>. </p>
<h2>Light pollution and cancer in children</h2>
<p>In 2012, I was invited to speak at a conference on causes of childhood cancer sponsored by the charity Children with Leukaemia UK. My charge was to discuss possible mechanisms by which excessive exposure to electric light at night might increase a child’s risk of cancer. I wrote a scientific paper on the subject that was <a href="http://cebp.aacrjournals.org/content/21/5/701.long">published</a> just before the conference. </p>
<p>This charity has a tragic origin story. The son of a very wealthy man in Britain, Eddie O’Gorman, died of leukemia in 1987 at age 14. His name was Paul. Before his death, Paul asked his parents to help other children with cancer. With the determined assistance of his sister Jean, his parents, Eddie and Marion, began fundraising. </p>
<p>Jean then died of breast cancer at age 29, only nine months after Paul’s death. Princess Diana heard of the tragedy, and offered to charter the charity in 1988. She remained involved with the activities of the charity until her own death in 1997. </p>
<p>The charity was renamed <a href="https://www.childrenwithcancer.org.uk">Children with Cancer UK</a> a few years ago.</p>
<p>The basis for concern about cancer in children is the fact that ill-timed electric light can disrupt circadian rhythms, and circadian disruption has been <a href="http://rstb.royalsocietypublishing.org/content/370/1667/20140120.long">implicated in cancers in adults</a>, although few if any studies have directly examined cancer in children. The evidence for an effect in children is indirect, but the issue is critical.</p>
<p>Leukemia is the most <a href="https://www.cancer.org/cancer/cancer-in-children/types-of-childhood-cancers.html">common childhood cancer</a>. It is a disease of uninhibited growth of white cells in the blood. These white cells are generated by stem cells, which when behaving normally produce just enough white cells for a healthy immune system to <a href="https://stemcells.nih.gov/info/2001report/chapter6.htm">function as it should</a>. When the stem cells go haywire, the result is leukemia. Recent studies have shown that the proliferation of <a href="http://www.cell.com/cell/fulltext/S0092-8674(16)30271-9">stem cells is under circadian control</a>. Thus, too much light at night could destabilize stem cell growth. </p>
<p>Children with Cancer UK will host its next scientific meeting in <a href="http://www.childhoodcancer2018.org.uk/programme.asp">Westminster, London, in September of this year</a>. I will focus on these new results of evening light-induced melatonin suppression in children for my presentation.</p>
<h2>Too much light at night early in life, even in utero</h2>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/214882/original/file-20180415-566-2ln76p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/214882/original/file-20180415-566-2ln76p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/214882/original/file-20180415-566-2ln76p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/214882/original/file-20180415-566-2ln76p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/214882/original/file-20180415-566-2ln76p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=504&fit=crop&dpr=1 754w, https://images.theconversation.com/files/214882/original/file-20180415-566-2ln76p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=504&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/214882/original/file-20180415-566-2ln76p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=504&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Too much light even in utero could be dangerous, some research suggests.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/upset-pregnant-woman-sitting-computer-desk-369968993?src=StTy2Yj8LPY4BD9INLTBDg-1-2">Andrey_Popov/Shutterstock.com</a></span>
</figcaption>
</figure>
<p>Early life, including in utero, is a <a href="http://www.oxfordreference.com/view/10.1093/oi/authority.20110803095447459">particularly vulnerable period</a>. The establishment of circadian rhythms begins early in gestation but is <a href="http://pediatrics.aappublications.org/content/112/2/373.long">not fully established at birth</a>, as any new parent becomes acutely aware. </p>
<p>For these reasons, research attention should be directed to the effects of ill-timed electric lighting on pregnant women, such as alterations in hormone production that could then affect fetal development. Scientists who study this also need to focus on developmental effects in young children and adolescents. </p>
<p>For example, it is unknown the extent to which night lights in the nursery alter the consolidation of circadian rhythmicity in infants, and whether toddlers exposed to highly lit evenings at home are at risk. I believe this is an urgent issue because adverse effects could launch a child on a lifetime trajectory of ill-health and early death.</p><img src="https://counter.theconversation.com/content/94952/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Richard G. "Bugs" Stevens does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>A recent study suggested that a chemical responsible for getting the body ready for sleep was suppressed in children by too much evening light. A circadian rhythm expert explains the dangers.Richard G. "Bugs" Stevens, Professor, School of Medicine, University of ConnecticutLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/948102018-04-12T18:07:21Z2018-04-12T18:07:21ZNight owls may have 10 percent higher risk of early death, study says<figure><img src="https://images.theconversation.com/files/214537/original/file-20180412-549-mvq9sq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Night owls, or people who have a hard time waking up in the morning, face health risks as a result.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/wake-tired-couple-touch-alarm-clock-148868597?src=t1Byv4JiGXhIXjv-2b3XDw-1-54">aslysun/Shutterstock.com</a></span></figcaption></figure><p>Do you wake up bright eyed and bushy-tailed, greeting the sunrise with cheer and vigor? Or are you up late into the night and dread the sound of your alarm clock? We call this inherent tendency to prefer certain times of day your “chronotype” (chrono means time). And it may be more than a scheduling issue. It has consequences for your health, well-being and mortality.</p>
<p>Being a <a href="http://www.sleep.theclinics.com/article/S1556-407X(15)00096-X/fulltext">night owl</a> has been associated with a range of health problems. For example, night owls have higher rates of obesity, high blood pressure and cardiovascular disease. Night owls are also more likely to have unhealthy behaviors, such as smoking, alcohol and drug use, and physical inactivity. </p>
<p>We study the health effects of being a night owl. In our recent study published in <a href="https://www.tandfonline.com/doi/full/10.1080/07420528.2018.1454458">Chronobiology International</a>, we found even worse news for the owls of the world: a higher risk of early death. </p>
<h2>Your very own biological clock</h2>
<p>Our bodies have their own internal time-keeping system, or clock. This clock would keep running even if a <a href="https://www.the-scientist.com/?articles.view/articleNo/45359/title/Cave-Dwellers--1938/">person were removed from the world</a> and hidden away in a dark cave (which some dedicated researchers did to themselves years ago!). We believe these internal clocks play an important role in health by <a href="https://www.nature.com/articles/417329a">anticipating the time of day and preparing the body</a> accordingly. </p>
<p>For example, as humans, we typically sleep at night, and our bodies start preparing for our habitual bedtime even before we try to fall asleep. Similarly, we eat during the day, so our body is prepared to process the food and nutrients efficiently during the daytime.</p>
<p>Our chronotype is also related to our biological clock. Morning larks’ biological clocks are set earlier. Their habitual bedtimes and wake times occur earlier in the day. Night owls have internal clocks set for later times. But are there any problems related to being a lark or owl, other than scheduling difficulties? Research suggests that there are; night owls tend to have worse health.</p>
<p>And, in our new study, we compared risk of dying between night owls and morning larks. In this study, death certificates were collected for an average of 6.5 years after the initial study visit to identify those who died. We found that night owls had a 10 percent increased risk of death over this six-and-a-half year period compared to larks. We also found that owls are more likely to have a variety of health problems compared to larks, particularly psychiatric disorders like depression, diabetes and neurological disorders.</p>
<p>The switch to daylight saving time in the U.S. (or summer time in the U.K.) only makes things more <a href="https://theconversation.com/the-dark-side-of-daylight-saving-time-91958">difficult for night owls</a>. There are <a href="https://www.cnn.com/2016/03/11/health/daylight-saving-time-health-effects/index.html">higher rates of heart attacks</a> following the switch to daylight savings, and we have to wonder if more night owls are at risk.</p>
<h2>Why do night owls have more health problems?</h2>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/214540/original/file-20180412-577-jhj9df.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/214540/original/file-20180412-577-jhj9df.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/214540/original/file-20180412-577-jhj9df.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/214540/original/file-20180412-577-jhj9df.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/214540/original/file-20180412-577-jhj9df.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=504&fit=crop&dpr=1 754w, https://images.theconversation.com/files/214540/original/file-20180412-577-jhj9df.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=504&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/214540/original/file-20180412-577-jhj9df.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=504&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Night owls’ health risks could be related to drinking, but they also could be due to loneliness.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/group-friends-having-drinks-night-club-580144114?src=K1K3PbIerGQKz9yD8Vn57A-1-2">Jacob Lund/Shutterstock.com</a></span>
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<p>We researchers do not fully understand why we see more health problems in night owls. It could be that being awake at night offers greater opportunity to consume alcohol and drugs. For some, being awake when everyone else is sleeping may lead to feelings of loneliness and increased risk of depression. It could also be related to our biological clocks.</p>
<p>As explained above, an important function of internal biological clocks is to anticipate when certain things, like sunrise, sleep and eating, will occur. Ideally, our behavior will match both our internal clock and our environment. What happens when it doesn’t? We suspect that “misalignment” between the timing of our internal clock and the timing of our behaviors could be detrimental over the long run. </p>
<p>A night owl trying to live in a morning lark world will struggle. Their job may require early hours, or their friends may want to have an early dinner, but they themselves prefer later times for waking, eating, socializing and sleep. This mismatch could lead to health problems in the long run.</p>
<h2>What can owls do?</h2>
<p>It is true that someone’s “chronotype” is (approximately) half <a href="https://www.ncbi.nlm.nih.gov/pubmed/28364486">determined by their genes</a>, but it is not entirely preordained. Many experts believe that there are <a href="https://www.wsj.com/articles/are-night-owls-better-off-changing-their-sleep-patterns-to-be-healthier-1491921962">behavioral strategies</a> that may help an individual who prefers evening. For example, gradually advancing your bedtime – going to bed a little earlier each night – may help to move someone out of the “night owl zone.”</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/214547/original/file-20180412-536-1he6vws.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/214547/original/file-20180412-536-1he6vws.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/214547/original/file-20180412-536-1he6vws.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/214547/original/file-20180412-536-1he6vws.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/214547/original/file-20180412-536-1he6vws.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=504&fit=crop&dpr=1 754w, https://images.theconversation.com/files/214547/original/file-20180412-536-1he6vws.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=504&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/214547/original/file-20180412-536-1he6vws.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=504&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Going to bed early is part of getting a good night’s sleep.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/close-portrait-beautiful-young-woman-sleeping-653167141?src=iFN76dNMOuXUESErV49h2g-2-5">fizkes/Shutterstock.com</a></span>
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</figure>
<p>A gradual advance is important because if you try to go to bed two to three hours earlier tonight, it won’t work, and you may give up. Once you achieve an earlier bedtime, maintain a regular schedule. Avoid shifting to later nights on weekends or free days because then you’ll be drifting back into night owl habits. Also, avoiding light at night will help, and this includes <a href="https://www.wsj.com/articles/are-night-owls-better-off-changing-their-sleep-patterns-to-be-healthier-1491921962">not staring into smartphones or tablets</a> before bed.</p>
<p>On a broader scale, flexibility in work hours would help to improve the health of night owls. Night owls who can schedule their day to match their chronotype may be better off. </p>
<p>It is important to make night owls aware about the risks associated with their chronotype and to provide them with this guidance on how to cope. We researchers need to identify which strategies will work best at alleviating the health risks and to understand exactly why they are at increased risk of these health problems in the first place.</p><img src="https://counter.theconversation.com/content/94810/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kristen Knutson receives funding from National Institutes of Health.</span></em></p><p class="fine-print"><em><span>Malcolm von Schantz does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Pity the poor night owls of the world, who already must adjust to a life that doesn’t align with their natural sleep patterns. Now it appears that being a night owl even raises the risk of death.Kristen Knutson, Associate Professor of Neurology, Northwestern UniversityMalcolm von Schantz, Professor of Chronobiology, University of SurreyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/939732018-03-28T14:22:48Z2018-03-28T14:22:48ZThe environmental case for keeping the clocks on summer time – all the time<figure><img src="https://images.theconversation.com/files/211961/original/file-20180326-148729-4r93ah.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption"></span> <span class="attribution"><span class="source">photosampler / shutterstock</span></span></figcaption></figure><p>Early to bed and early to rise makes a man healthy, wealthy and … also energy efficient, as it turns out.</p>
<p>After 1am on Sunday night here in Oxford the time suddenly jumped forward to 2am – the UK is now officially on “British Summer Time”, where it will remain for the next seven months. The rest of Europe also put its clocks forward at the same moment, while the US and Canada moved to summer time earlier in March. Collectively, this is known as daylight saving time. </p>
<p>But what if all these countries kept to summer time throughout the winter? About a decade ago researchers at the University of Cambridge made a strong case that, in the UK at least, it would have <a href="https://www.ifm.eng.cam.ac.uk/uploads/Research/CTM/Resources/gmt_cronin_garnsey_rev_oct10.pdf">a range of positive effects</a>. Twelve months of summer time could reduce road deaths and crime, boost business and trade and also reduce energy consumption at peak times by <a href="https://pdfs.semanticscholar.org/962f/009bef1eabbafe443be581b57e5fe4d210a7.pdf">up to 8%</a>. All of this is possible because our most active periods would be better aligned with daylight hours.</p>
<p>Shifting the timing of electricity use has gone up the academic agenda for another reason. <a href="http://www.energy-use.org/background.php">Flexible demand</a> has the potential to save billions in the integration of renewables, such as wind and solar.</p>
<p>The logic is simple: the highest energy demand occurs in winter around 5.30pm. This is when people come home and many businesses are still open. It’s also when it is cold and dark and we need extra energy for heat and light. Yet, output from low-carbon solar power is pretty much guaranteed to be zero.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/211984/original/file-20180326-159072-1xb0ij7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/211984/original/file-20180326-159072-1xb0ij7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/211984/original/file-20180326-159072-1xb0ij7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=378&fit=crop&dpr=1 600w, https://images.theconversation.com/files/211984/original/file-20180326-159072-1xb0ij7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=378&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/211984/original/file-20180326-159072-1xb0ij7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=378&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/211984/original/file-20180326-159072-1xb0ij7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=475&fit=crop&dpr=1 754w, https://images.theconversation.com/files/211984/original/file-20180326-159072-1xb0ij7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=475&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/211984/original/file-20180326-159072-1xb0ij7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=475&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">5pm in December – or 6pm?</span>
<span class="attribution"><span class="source">mvtstockshot / shutterstock</span></span>
</figcaption>
</figure>
<p>If British Summer Time was continued through the winter, the peak-demand problem would be reduced. Everyone would get up an hour earlier, work earlier and come home earlier, often when it is still light. Activity would still peak at around 5.30pm human time, but that same time would be earlier relative to sunset. </p>
<p>Given that lighting alone may be responsible for <a href="https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/208097/10043_R66141HouseholdElectricitySurveyFinalReportissue4.pdf">20% of peak demand</a> in the UK, there is lots of scope for saving energy. One review found that using energy at different times could lead to peak reductions of <a href="https://www.sciencedirect.com/science/article/pii/S0301421512006076">up to 8%</a>.</p>
<p>In lighter evenings there might even still be some solar power available to further reduce the net demand for fossil fuels. The savings in the evening would exceed any potential increase in the mornings. </p>
<p>So why don’t we talk more about how daylight saving hours could help the effort to decarbonise? One reason is political economy – while getting up an hour earlier makes sense to an expert in energy policy or road safety, it won’t necessarily be popular with the public (not to mention <a href="http://www.bbc.co.uk/news/uk-scotland-37798028">Scottish farmers</a> or teenage children).</p>
<p>This is the same problem that affects many other potentially very sensible energy saving measures: as soon as there is even a remote chance of inconveniencing people, it is likely not to see the light of day. This is part of the reason why energy policy making is dominated by measures to boost supply such as new nuclear plants, fracking, or support for renewables. Tampering with the demand side requires a lot of political courage.</p>
<p>However, we may be able to put a more positive spin on it. Why should changing what we call “7am” to “8am” make such a difference anyway? After all, it is just a relabelling exercise.</p>
<p>It is fascinating how an entire society re-synchronises its activities based on a change of the clock hands. Yet if people stuck to their own rhythm they could avoid the worst rush hours and even get home in daylight during the winter.</p>
<p>Of course it is not that simple. Our daily rhythms are strongly reinforced by traditional conventions, such as working hours, schooling hours and shop opening hours. It began in the 19th century with factories using time to synchronise their workforce into shifts. With the arrival of the railways, <a href="http://www.bbc.co.uk/blogs/wales/entries/8d6d68fa-1e6a-39e1-9f29-232450445f41">clocks across the country were synchronised</a> and millions of people began to operate to the same rhythm – not their natural rhythm, but the clock rhythm.</p>
<p>There are some obvious benefits to having a workforce in the same place at the same time. However, when looking at the system as a whole, synchronisation brings with it some serious challenges, most notably peak demand constraints.</p>
<p>It may therefore not be all that helpful to shift everyone’s day by one hour with a nationally synchronised clock change. Allowing for some more diversity to develop instead could be advantageous. More flexible working hours could reduce and spread peaks. This could even be encouraged regionally, given that Cornwall, on England’s south coast, faces very different daylight conditions than, say, north Scotland.</p>
<p>You don’t need to wait for the government either. Next autumn, when the clocks go back, be a rebel and just go to bed one hour earlier – that is, don’t change anything. You’ll not only reduce energy demand, but also help to diversify it.</p><img src="https://counter.theconversation.com/content/93973/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Philipp Grünewald is part of the EPSRC-funded METER project which investigates what we use electricity for, and how we can reduce consumption at peak times.</span></em></p>Daylight savings time means our most active periods are better aligned with daylight hours.Philipp Grünewald, Fellow in Lower Carbon Futures, Environmental Change Institute, University of OxfordLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/930482018-03-09T11:38:59Z2018-03-09T11:38:59Z100 years later, the madness of daylight saving time endures<figure><img src="https://images.theconversation.com/files/209597/original/file-20180308-30994-bzca2a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Unfortunately, there's not an unlimited amount of daylight that we can squeeze out of our clocks.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/vintage-clock-over-grunge-paper-background-74332531?src=_bKFXEFXzkU0bsCQnDic_A-3-24">igorstevanovic/Shutterstock.com</a></span></figcaption></figure><p>One hundred years after Congress passed the first daylight saving legislation, more and more people are doubting the wisdom of changing the clocks. </p>
<p>In August, the EU Commission <a href="https://www.bbc.com/news/world-europe-45366390">proposed ending the biannual practice</a>.</p>
<p>Last winter, lawmakers in Florida passed the <a href="http://www.miamiherald.com/news/state/florida/article203781769.html">“Sunshine Protection Act</a>,” which will make daylight saving a year-round reality in the Sunshine State. </p>
<p>If approved by the federal government, this will effectively move Florida’s residents one time zone to the east, aligning cities from Jacksonville to Miami with Nova Scotia rather than New York and Washington, D.C. </p>
<p>The cost of rescheduling international and interstate business and commerce hasn’t been calculated. Instead, relying on the same overly optimistic math that led the original proponents of daylight saving <a href="https://www.jstor.org/stable/30045549?seq=1#page_scan_tab_contents">to predict</a> vast energy savings, crisper farm products harvested before the morning dew dried and lessened eye strain for industrial workers, Florida legislators are <a href="http://www.miamiherald.com/news/state/florida/article203781769.html">lauding the benefits</a> of putting “more sunshine in our lives.” </p>
<p>It’s absurd – and fitting – that a century later, opponents and supporters of daylight saving are still not sure exactly what it does. Despite its name, daylight saving has never saved anyone anything. But it has proven to be a fantastically effective driver of retail spending. </p>
<h2>Making the trains run on time</h2>
<p>For centuries people set their clocks and watches by looking up at the sun and estimating, which yielded wildly dissimilar results between (and often within) cities and towns. </p>
<p>To railroad companies around the world, that wasn’t acceptable. They needed synchronized, predictable station times for arrivals and departures, so they proposed splitting up the globe <a href="https://greenwichmeantime.com/info/time-zones-history/">into 24 time zones</a>.</p>
<p>In 1883, the economic clout of the railroads allowed them to replace sun time with standard time with no legislative assistance and little public opposition. The clocks were calm for almost 30 years, apart from an annual debate in the British Parliament over whether to pass a Daylight Saving Act. While proponents argued that shoving clocks ahead during summer months would reduce energy consumption and encourage outdoor recreation, the opposition won out.</p>
<p>Then, in 1916, Germany suddenly adopted the British idea in hopes of conserving energy for its war effort. Within a year, Great Britain followed suit. And despite fanatical opposition from the farm lobby, so would the United States.</p>
<h2>From patriotic duty to moneymaking scheme</h2>
<p>A law requiring Americans to lose an hour was confounding enough. But Congress also tacked on the legal mandate for the four continental time zones. The patriotic rationale for daylight saving <a href="https://books.google.com/books?id=CLkRx5PDAbgC&lpg=PP1&dq=spring%20forward%20michael%20dowling&pg=PP1#v=onepage&q&f=false">went like this</a>: Shifting one hour of available light from the very early morning (when most Americans were asleep) would reduce the demand for domestic electrical power used to illuminate homes in the evening, which would spare more energy for the war effort. </p>
<p>On March 19, 1918, Woodrow Wilson signed the <a href="http://www.legisworks.org/congress/66/publaw-40.pdf">Calder Act</a> requiring Americans to set their clocks to standard time; less than two weeks later, on March 31, they would be required to abandon standard time and push their clocks ahead by an hour for the nation’s first experiment with daylight saving.</p>
<p>It didn’t go smoothly. In 1918, Easter Sunday fell on March 31, which led to a lot of latecomers to church services. Enraged rural and evangelical opponents thereafter blamed daylight saving for subverting sun time, or “God’s time.” Newspapers were deluged by letter writers complaining that daylight saving upset astronomical data and made almanacs useless, prevented Americans from enjoying the freshest early morning air, and even browned out lawns unaccustomed to so much daylight.</p>
<p>Within a year, daylight saving was repealed. But like most weeds, the practice thrived by neglect.</p>
<p>In 1920, New York and dozens of other cities adopted their own metropolitan daylight saving policies. The Chamber of Commerce <a href="https://www.jstor.org/stable/30045549?seq=1#page_scan_tab_contents">spurred along this movement</a> on behalf of department store owners, who had noticed that later sunset times encouraged people to stop and shop on their way home from work.</p>
<p>By 1965, 18 states observed daylight saving six months a year; some cities and towns in 18 other states observed daylight saving for four, five or six months a year; and 12 states stuck to standard time.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/209596/original/file-20180308-30954-1ocd2eo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/209596/original/file-20180308-30954-1ocd2eo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=559&fit=crop&dpr=1 600w, https://images.theconversation.com/files/209596/original/file-20180308-30954-1ocd2eo.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=559&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/209596/original/file-20180308-30954-1ocd2eo.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=559&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/209596/original/file-20180308-30954-1ocd2eo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=702&fit=crop&dpr=1 754w, https://images.theconversation.com/files/209596/original/file-20180308-30954-1ocd2eo.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=702&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/209596/original/file-20180308-30954-1ocd2eo.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=702&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Actress Barbara Lawrence reminds television viewers to set the clock ahead, from 1 a.m. to 2 a.m., on April 29, 1956.</span>
<span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Watchf-AP-A-USA-APHS412039-Daylight-Savings-Time/1068f7c24eb64a9f8554b45ded215730/3/0">AP Photo</a></span>
</figcaption>
</figure>
<p>This wasn’t exactly ideal. A 35-mile bus trip from Steubenville, Ohio, to Moundsville, West Virginia, passed through <a href="https://books.google.com/books?id=CLkRx5PDAbgC&pg=PA129&lpg=PA129&dq=daylight+saving+steubenville+oh+to+moundsville+wv&source=bl&ots=olE0QNwZGJ&sig=EnjrItjGbyxaC_rlsejoP8fPG8g&hl=en&sa=X&ved=0ahUKEwjXg-OF093ZAhUV0IMKHbfoDJA4FBDoAQg1MAI#v=onepage&q=daylight%20saving%20steubenville%20oh%20to%20moundsville%20wv&f=false">seven distinct local time zones</a>. The U.S. Naval Observatory <a href="https://books.google.com/books?id=CLkRx5PDAbgC&pg=PR14&lpg=PR14&dq=%22the+world%27s+worst+timekeeper%22&source=bl&ots=olE0QNxSCM&sig=o49o72N4-bdTAzU-Pk_pq4_hpVY&hl=en&sa=X&ved=0ahUKEwjh4IWD1N3ZAhWBxIMKHRhHDxsQ6AEILDAB#v=onepage&q=%22the%20world's%20worst%20timekeeper%22&f=false">dubbed</a> the world’s greatest superpower “the world’s worst timekeeper.”</p>
<p>So, in 1966, Congress passed the <a href="https://www.gpo.gov/fdsys/pkg/STATUTE-80/pdf/STATUTE-80-Pg107.pdf">Uniform Time Act</a>, which mandated six months of standard time and six of daylight saving.</p>
<h2>Great for golf – but what about everyone else?</h2>
<p>Why do we still do it? </p>
<p>Today we know that changing the clocks does influence our behavior. For example, later sunset times <a href="https://www.nytimes.com/1917/01/07/archives/foster-for-longer-day-giants-secretary-favors-measure-to-advance.html">have dramatically increased</a> participation in afterschool sports programs and attendance at professional sports events. In 1920, The Washington Post reported that golf ball sales in 1918 – the first year of daylight saving – increased by 20 percent. </p>
<p>And when Congress extended daylight saving from six to seven months in 1986, the golf industry estimated that extra month was worth <a href="https://books.google.com/books?id=CLkRx5PDAbgC&pg=PA198&lpg=PA198&dq=daylight+saving+national+golf+foundation&source=bl&ots=olE0QNz_xL&sig=IDxl2x_sC3RyC5oKN-72zIpXs4M&hl=en&sa=X&ved=0ahUKEwj01N6h3t3ZAhWN0YMKHeHLB2MQ6AEIPzAC#v=onepage&q=daylight%20saving%20national%20golf%20foundation&f=false">as much as US$400 million</a> in additional equipment sales and green fees. To this day, the Nielsen ratings for even the most <a href="http://variety.com/2017/tv/news/american-crime-season-3-premiere-ratings-1202010147/">popular television shows decline precipitously when we spring forward</a>, because we go outside to enjoy the sunlight. </p>
<p>But the promised energy savings – the presenting rationale for the policy – have never materialized. </p>
<p>In fact, the <a href="https://theconversation.com/is-daylight-saving-time-worth-the-trouble-research-says-no-86739">best studies</a> we have prove that Americans <a href="https://www.wsj.com/articles/SB120406767043794825">use more domestic electricity</a> when they practice daylight saving. Moreover, when we turn off the TV and go to the park or the mall in the evening sunlight, Americans don’t walk. We get in our cars and drive. Daylight saving actually increases gasoline consumption, and it’s a fallacious substitute for genuine energy conservation policy.</p>
<p>Lawmakers in Florida, of all places, ought to know that year-round daylight saving is not such a bright idea – especially in December and January, when most residents of the Sunshine State won’t see sunrise until about 8 a.m.</p>
<p>On Jan. 8, 1974, Richard Nixon forced Floridians and the entire nation into <a href="http://www.presidency.ucsb.edu/ws/?pid=4034">a year-round daylight saving</a> – a vain attempt to stave off an energy crisis and lessen the impact of an OPEC oil embargo. </p>
<p>But before the end of the first month of daylight saving that January, eight children died in traffic accidents in Florida, and a spokesperson for Florida’s education department <a href="https://www.nytimes.com/1974/01/31/archives/schools-ask-end-to-daylight-time-pressure-follows-success-in-easing.html">attributed six of those deaths</a> directly to children going to school in darkness.</p>
<p>Lesson learned? Apparently not. </p>
<p><em>Editor’s note: This is an updated version of an article that originally was published March 9, 2018.</em></p><img src="https://counter.theconversation.com/content/93048/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michael Downing does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The original arguments Congress made for ‘springing ahead’ have been thoroughly debunked. So why are they still being used by legislators today?Michael Downing, Lecturer in Creative Writing, Tufts UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/919592018-03-08T11:44:07Z2018-03-08T11:44:07ZWant better sex? Try getting better sleep<figure><img src="https://images.theconversation.com/files/208694/original/file-20180302-65544-1e7umuo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Sleep affects sex, and sex affects sleep. It's important to pay attention to both. </span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/side-view-beautiful-young-couple-sleeping-499192603?src=yH4KX0edA356PgbPhELeKA-1-4">VGstockstudio/Shutterstock.com </a></span></figcaption></figure><p><a href="https://www.cdc.gov/media/releases/2016/p0215-enough-sleep.html">One in 3 American adults</a> do not get enough sleep. Sexual issues are also common, with as many as <a href="https://link.springer.com/article/10.1007/s11920-996-0006-2">45 percent of women and 31 percent of men</a> having a concern about their sex life. While these might seem like distinct concerns, they are actually highly related. </p>
<p>How are sleep and sex related? I’ll state the obvious: We most commonly sleep and have sex in the same location – the bedroom. Less obvious but more important is that lack of sleep and lack of sex share some common underlying causes, including stress. Especially important, lack of sleep can lead to sexual problems and a lack of sex can lead to sleep problems. Conversely, a good night’s sleep can lead to a greater interest in sex, and orgasmic sex can result in a better night’s sleep.</p>
<p>I am a sex educator and researcher who has published several studies on the effectiveness of self-help books in enhancing sexual functioning. I have also written two sexual self-help books, both based in research findings. My latest book, “<a href="http://drlauriemintz.com/books/becoming-cliterate/">Becoming Cliterate: Why Orgasm Equality Matters – and How to Get It</a>,” is aimed at empowering women to reach orgasm. More pertinent to the connection between sleep and sex, my first book, “<a href="http://drlauriemintz.com/books/a-tired-womans-guide-to-passionate-sex/">A Tired Woman’s Guide to Passionate Sex</a>,” was written to help the countless women who say they are too exhausted to be interested in sex. </p>
<h2>The effect of sleep on sex among women</h2>
<p>The reason I wrote a book for women who are too tired for sex is because women are disproportionately affected by both sleep problems and by low sexual desire, and the relationship between the two is indisputable. <a href="https://sleepfoundation.org/sleep-topics/women-and-sleep">Women are more likely than men to have sleep problems</a>, and <a href="http://onlinelibrary.wiley.com/doi/10.1111/j.1471-0528.2002.01002.x/full">the most common sexual complaint that women bring to sex therapists and physicians is low desire</a>. Strikingly, being too tired for sex is the top reason that women give for their loss of desire. </p>
<p>Conversely, getting a good night’s sleep can increase desire. <a href="http://onlinelibrary.wiley.com/doi/10.1111/jsm.12858/full">A recent study</a> found that the longer women slept, the more interested in sex they were the next day. Just one extra hour of sleep led to a 14 percent increase in the chances of having a sexual encounter the following day. Also, in this same study, more sleep was related to better genital arousal. </p>
<p>While this study was conducted with college women, those in other life stages have even more interrelated sleep and sex problems. Menopause involves a complicated interaction of biological and psychological issues that are associated with both sleep and sex problems. Importantly, <a href="http://online.liebertpub.com/doi/pdf/10.1089/jwh.2009.1800">a recent study</a> found that among menopausal women, sleep problems were directly linked to sexual problems. In fact, sleep issues were the only menopausal symptom for which such a direct link was found. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/208730/original/file-20180302-65544-z1986.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/208730/original/file-20180302-65544-z1986.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/208730/original/file-20180302-65544-z1986.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/208730/original/file-20180302-65544-z1986.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/208730/original/file-20180302-65544-z1986.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/208730/original/file-20180302-65544-z1986.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/208730/original/file-20180302-65544-z1986.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Motherhood is great, but the demands of a new baby can exhaust a new mother. Sleep can become more appealing than sex as a result.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/young-mother-holding-her-newborn-child-329743067?src=f1ribZpMHQnw-hVqRW2jGg-1-13">FamVeld/Shutterstock.com</a></span>
</figcaption>
</figure>
<p>Interrelated sleep and sexual issues are also prevalent <a href="https://sleepfoundation.org/sites/default/files/Poll%20Release%20-%20FINAL.pdf">among mothers</a>. Mothers of new babies are the least likely to get a good night’s sleep, mostly because they are caring for their baby during the night. However, ongoing sleep and sexual issues for mothers are often caused by having too much to do and the associated stress. Women, who are married with school-age children and working full time, are the most likely to report insomnia. Still, part-time working moms and moms who don’t work outside the home report problems with sleep as well.</p>
<p>While fathers also struggle with stress, there is <a href="https://www.ncbi.nlm.nih.gov/pubmed/10825779">evidence</a> that stress and the <a href="http://www.apa.org/news/press/releases/stress/2010/gender-stress.pdf">resulting sleepless nights</a> dampen women’s sexual desire more than they do men’s. Some of this is due to hormones. Both <a href="https://www.ncbi.nlm.nih.gov/pubmed/9415946">insufficient sleep</a> and <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2703719/">stress</a> result in the release of cortisol, and <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3880087/">cortisol decreases testosterone</a>. Testosterone plays a major role in the sex drive of women and men. Men have significantly more testosterone than women. So, thinking of testosterone as a tank of gas, the cortisol released by stress and lack of sleep might take a woman’s tank to empty, yet only decrease a man’s tank to half full. </p>
<h2>The effect of sleep on sex among men</h2>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/208731/original/file-20180302-65547-kslsni.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/208731/original/file-20180302-65547-kslsni.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/208731/original/file-20180302-65547-kslsni.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/208731/original/file-20180302-65547-kslsni.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/208731/original/file-20180302-65547-kslsni.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=504&fit=crop&dpr=1 754w, https://images.theconversation.com/files/208731/original/file-20180302-65547-kslsni.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=504&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/208731/original/file-20180302-65547-kslsni.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=504&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Even young men can lose interest in sex if they are sleep-deprived.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/front-view-tired-man-sleeping-on-339327623?src=SqCH9BDwf03dBpL7NNHsjA-1-32">Antonio Guillem/Shutterstock.com</a></span>
</figcaption>
</figure>
<p>Although lack of sleep and stress seems to affect women’s sexual functioning more than men’s, men still suffer from interrelated problems in these areas. <a href="https://jamanetwork.com/journals/jama/fullarticle/1029127">One study</a> found that, among young healthy men, a lack of sleep resulted in decreased levels of testosterone, the hormone responsible for much of our sex drive. <a href="http://onlinelibrary.wiley.com/doi/10.1111/j.1743-6109.2009.01372.x/full">Another study</a> found that among men, sleep apnea contributed to erectile dysfunction and an overall decrease in sexual functioning. Clearly, among men, lack of sleep results in diminished sexual functioning. </p>
<p>I could not locate a study to prove this, as it stands to reason that the reverse is also true. That is, it seems logical that, as was found in the <a href="http://onlinelibrary.wiley.com/doi/10.1111/jsm.12858/full">previously mentioned study among women</a>, for men a better night’s sleep would also result in better sexual functioning.</p>
<h2>The effect of sex on sleep</h2>
<p>While sleep (and stress) have an effect on sex, the reverse is also true. That is, sex affects sleep (and stress). <a href="https://www.cnn.com/2017/06/01/health/sex-sleep-kerner/index.html">According to sex expert Ian Kerner</a>, too little sex can cause sleeplessness and irritability. Conversely, there is some <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2703719/">evidence</a> that the stress hormone cortisol decreases after orgasm. There’s also <a href="https://www.cqu.edu.au/cquninews/stories/research-category/2016/can-sex-be-repositioned-as-a-sleep-therapy">evidence</a> that oxytocin, the “<a href="https://www.psychologytoday.com/basics/oxytocin">love hormone</a>” that is released after orgasm, results not only in increased feelings of connection with a partner, but in better sleep. </p>
<p>Additionally, <a href="https://www.cnn.com/2017/06/01/health/sex-sleep-kerner/index.html">experts claim</a> that sex might have gender-specific effects on sleep. Among women, orgasm increases estrogen, which leads to deeper sleep. Among men, the hormone prolactin that is secreted after orgasm results in sleepiness.</p>
<h2>Translating science into more sleep and more sex</h2>
<p>It is now clear that a hidden cause of sex problems is sleeplessness and that a hidden cause of sleeplessness is sex problems. This knowledge can lead to obvious, yet often overlooked, cures for both problems. Indeed, experts have suggested that <a href="http://online.liebertpub.com/doi/pdf/10.1089/jwh.2009.1800">sleep hygiene can help alleviate sexual problems</a> and that <a href="https://www.cqu.edu.au/cquninews/stories/research-category/2016/can-sex-be-repositioned-as-a-sleep-therapy">sex can help those suffering from sleep problems</a>. </p>
<p>Perhaps, then, it is no surprise that both sleep hygiene suggestions and suggestions for enhanced sexual functioning have some overlap. For example, <a href="https://www.cnn.com/2017/06/01/health/sex-sleep-kerner/index.html">experts suggest</a> sticking to a schedule, both for sleep and for sexual encounters. They also recommend decreasing smartphone usage, both before bed and when spending time with a partner. The bottom line of these suggestions is to make one’s bedroom an exclusive haven for the joys of both sleep and sex.</p><img src="https://counter.theconversation.com/content/91959/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Laurie Mintz does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Research demonstrates a two-way relationship between sleep problems and sexual problems, as well as between satisfying sex and sound sleep. If you want better sex, you need better sleep.Laurie Mintz, Professor of Psychology, University of FloridaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/918032018-03-07T11:41:25Z2018-03-07T11:41:25ZWhy are we so sleep deprived, and why does it matter?<figure><img src="https://images.theconversation.com/files/208934/original/file-20180305-146645-8d89su.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">As many as 70 million Americans may not be getting enough sleep. Men get fewer hours of sleep than women.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/monday-morning-again-186566120?src=xq4hLhcCUpruA-fFOIbQfQ-1-28">Akos Nagy/Shutterstock.com</a></span></figcaption></figure><p>As we prepare to “spring forward” for daylight saving time, many of us dread the loss of the hour’s sleep we incur by moving our clocks forward. For millions, the loss will be an added insult to the inadequate sleep they experience on a daily basis.</p>
<p>Surveys show that <a href="https://www.cdc.gov/sleep/data_statistics.html">40 percent of American adults get less</a> than the nightly minimum of seven hours of sleep recommended by the American Academy of Sleep Medicine and the National Sleep Foundation. The National Institutes for Health estimate that between <a href="https://www.ncbi.nlm.nih.gov/pubmed/20669438">50 million and 70 million people</a> do not get enough sleep. These recommendations for minimal sleep are based on a review of many scientific studies evaluating the role of sleep in our bodies and the effects of sleep deprivation on our ability of our body to function at our peak performance level. </p>
<p>I am a <a href="https://scholar.google.com/citations?user=q5xsCiYAAAAJ&hl=en">neurologist</a> at the University of Florida who has studied the effects of both traumatic brain injury and sleep impairment on the brain. I have seen the effects of sleep impairment and the significant effects it can have.</p>
<p>According to the National Sleep Foundation, American adults currently average <a href="http://news.gallup.com/poll/166553/less-recommended-amount-sleep.aspx">6.9 hours of sleep</a> per night compared with the 1940s, when most American adults were averaging 7.9 hours a night, or one hour more each night. In fact, in 1942, 84 percent of Americans got the recommended seven to nine hours; in 2013, that number had dropped to <a href="http://news.gallup.com/poll/166553/less-recommended-amount-sleep.aspx">59 percent</a>. Participants in that same Gallup poll reported on average they felt they needed 7.3 hours of sleep each night but were not getting enough, causing an average nightly sleep debt of 24 minutes. <a href="https://finance.yahoo.com/news/exclusive-fitbits-6-billion-nights-sleep-data-reveals-us-110058417.html">Fitbit</a> in January 2018 announced results of a study it conducted of 6 billion nights of its customers’ sleep and reported that men actually get even less than women, about 6.5 hours. </p>
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<h2>Why sleep matters</h2>
<p>The problems caused by sleep shortage go beyond tiredness. In recent years, <a href="https://www.ncbi.nlm.nih.gov/pubmed/27397854">studies</a> have shown that adults who were short sleepers, or those who got less than seven hours in 24 hours, were more likely to report <a href="https://www.cdc.gov/sleep/data_statistics.html">10 chronic health conditions</a>, including heart disease, diabetes, obesity, asthma and depression, compared to those who got enough sleep, that is, seven or more hours in a 24-hour period.</p>
<p>There are more challenges for children, as they are thought to have an increased sleep need compared to adults. The <a href="http://jcsm.aasm.org/ViewAbstract.aspx?pid=30652">American Academy of Sleep Medicine recommends</a> that children 6 to 12 years of age should sleep nine to 12 hours a day and teens 13 to 18 should sleep eight to 10 hours daily on a regular basis to promote optimal health.</p>
<p>A Sleep Foundation poll of parents suggested that American children are getting one hour of sleep or more per night less than what their body and brain require.</p>
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<p>Researchers have found that <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1978403/">sleep deprivation of even a single hour</a> can have a harmful effect on a child’s developing brain. Inadequate sleep can affect synaptic plasticity and memory encoding, and it can result in inattentiveness in the classroom.</p>
<p>Every one of our biological systems is affected by sleep. When we don’t sleep long enough or when we experience poor quality of sleep, there can be serious biological consequences.</p>
<p>When we are sleep deprived, our bodies become more aroused through an enhanced <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3538178/">sympathetic nervous system</a>, known as “fight or flight.” There is a greater propensity for increased blood pressure and possible risk of coronary heart disease. Our <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3538178/">endocrine system</a> releases more cortisol, a stress hormone. The body has less glucose tolerance and greater insulin resistance, which in the long term can cause an increased risk of Type 2 diabetes. Also, sleep deprivation causes a reduction in growth hormone and muscle maintenance.</p>
<p>We also rely on sleep to maintain our metabolism. Sleep deprivation can lead to decreased release of the hormone leptin and increased release of the hormone ghrelin, which can be associated with increased appetite and weight gain. </p>
<p>The human body also relies on sleep to help with our immune system. Sleep deprivation is associated with increased inflammation and decreased antibodies to influenza and decreased resistance to infection.</p>
<p>Inadequate sleep has been associated with a <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3538178/">negative effect on mood</a> as well as decreased attention and increased memory difficulty. In addition, someone who is sleep deprived may experience a decrease in pain tolerance and in reaction times. Occupational studies have associated sleep deprivation with decreased performance, increased car accidents, and more days missed from work. </p>
<h2>The role of the brain</h2>
<p>Researchers have known for a while that brain health is an important aspect of sleep. Notably, sleep is an important part of memory consolidation and learning. </p>
<p>Newer research has suggested another important aspect of sleep for our brain: There is a system for the elimination of <a href="https://www.nih.gov/news-events/nih-research-matters/how-sleep-clears-brain">possibly harmful proteins</a> such as abnormal variants of amyloid. This waste removal process, using what is known as the <a href="https://www.ncbi.nlm.nih.gov/pubmed/28859995">glymphatic system</a>, relies on sleep to effectively eliminate these proteins from the brain. These are the same proteins found to be elevated in patients with Alzheimer’s disease. Studies show that older adults with less sleep have greater accumulations of these proteins in their brains.</p>
<p>Our sleep-wake cycle is regulated by the <a href="https://theconversation.com/understanding-the-genes-that-make-our-circadian-clocks-tick-67356">circadian system</a>, which helps signal the brain to sleep using the release of the natural hormone melatonin. It turns out that our body’s system for regulating melatonin and our sleep schedule is most powerfully controlled by light. </p>
<p>There are <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4812508/">cells in the retina of our eye</a> that communicate directly with the brain’s biological clock regulators located in the hypothalamus and this pathway is most affected by light. These neurons have been found to be most affected by light waves from the blue spectrum or blue light. This is the kind of light <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4734149/">most prominent in electronic</a> lights from computers and smartphones. This has become a modern challenge that can adversely affect our natural sleep-wake cycle.</p>
<p>Additional factors that can hamper sleep include pain conditions, medications for other conditions, and the increased demands and connectedness of modern society.</p>
<p>As we prepare for daylight saving time, we can be mindful that <a href="https://www.tandfonline.com/doi/abs/10.3109/02699052.2014.983978">many athletes have been including planned sleep extensions</a> (sleeping longer than usual) into their schedule to enhance performance and that many professional sports teams have hired sleep consultants to help assure their athletes have enough sleep. Perhaps we should have a similar game plan as we approach the second Sunday in March.</p><img src="https://counter.theconversation.com/content/91803/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michael S. Jaffee does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Few things seem to matter to our health as much as a good night’s sleep, but fewer and fewer of Americans are getting it. A neurologist explains why sleep is so important.Michael S. Jaffee, Vice chair, Department of Neurology, University of FloridaLicensed as Creative Commons – attribution, no derivatives.