Happy Leap Day!

It's February 29, which is Leap Day.  It takes the earth 365 days and 6 hours to travel around the sun.  Since there are only 365 days in a year, someone thought of adding on an extra day every four years to stay on track.  It only happens every four years in years that can be divided evenly by the number 4.  

(BTW, it's not like I have a giant brain or anything; I lifted all of this from that great encyclopedia in the sky, Wikipedia.)