Julius Caesar created leap year to account for the fact that the trip around the sun doesn't conform to a neat package of complete days. In 1585 Pop Gregory XIII tried a new calendar. After that leap years have occurred in years divisible by four except for those divided by 200 and not divisible by 400. Individuals born on February 29 are called Leapers. What to do with an extra day? Take a Leap. Commit yourself to a day of writing about something out of your realm.