Leap years were devised in Julius Caesar's time, to fix the pesky problem that Earth's year isn't exactly 365 days. But 15 centuries later, our calendars were still slightly askew.
2016 has been a long year, but it'll be made slightly longer care of a leap second. But why do we need such things?
We will get an 'extra' day this year, February 29. Where do these quadrennial liberties with our calendar originate?