It takes the earth 365¼ days to orbit the sun. Therefore, every four years it's a Leap Year and we have an extra day called Leap Day.
According to infoplease.com
Timeanddate.com reports, "Julius Caesar introduced Leap Years in the Roman empire over 2000 years ago."
"Leap Year" is also the title of a movie starring Amy Adams about a woman who wants to follow Irish folklore and propose to her boyfriend on Feb. 29.