Above: Today's Google logo for leap day. It has a bunny representing the 28th of February next to one representing the 1st of March, and a bunny representing February 29 leaping between them! See it at google.com , or if you are reading this another day, click here . 2016 is a very special year! Why? It is a leap year, which is rare and only happens every 4 years! On a leap year, an extra day is added to February, which is February 29, commonly called "Leap Day". But why exactly does this happen? The time it takes Earth to completely orbit the sun is different than the amount a year lasts on the average calendar used (AKA, the Gregorian Calendar). We say that there are 365 days in a year, but there are technically 365.24 days or a little over a day. That is why in order to keep our clocks and calendars in sync with Earth's ever-changing seasons, we add leap seconds, and also leap years. Believe it or not, originally, the ancient Roman calendar ha...