It’s February 29th again but have you really even noticed? What’s the big deal anyway? It’s leap year folks, and in an effort to realign our calendar, it is necessary. Simply put: it takes the earth approximately 365 days, 5 hours, 48 minutes, and 46 seconds long to revolve around the sun. To make matters worse the planet’s speed along its orbit is not entirely consistent and occasionally leap seconds are added to our clocks to compensate. If this kind of talk leads you to believe that your time keeping device may need to be verified you can check out The Official US Time from NIST.
The bottom line concerning leap year is that the calendar has changed dramatically throughout our history. In an attempt to quantify the universe we live in we have come up short with our categories called days, minutes, and hours, and we have shored the whole thing up with an extra day every four years with exceptions. In every respect, including our calendar, we cannot with precise accuracy divide time into nice little squares onto a calendar. If one wishes to understand the mathematics behind the leap year please read PIERCE EXPANSIONS AND RULES FOR THE DETERMINATION OF LEAP YEARS by Jeffrey Shallit.
I could attempt to explain the leap year and why it is important, but this video from CGPGrey’s Channel does a much better job than I could ever do.