Leap Day

2012 is a leap year, meaning that February, the shortest month, has an extra day, bringing the year to 366 days. This notable event comes only every four years. This year, Leap Day is on Wednesday, February 29.

Usually, our year is 365 days long. Except that it's not: A full cycle of seasons is actually 365 days, 5 hours, 49 minutes, and 16 seconds long, or about 365.25 days. Over time, the extra quarter of a day adds up, and without Leap Day, the calendar would be one day out of sync with the seasons. After 30 years, it would be about a week off, and after 100 years, it would be nearly a month off.

Leap Year has been around for 2,000 years, since Julius Caesar created the 365-day calendar, although Caesar's astronomer, Sosigenes, get s credit for adding an extra day in February every four years.