Why is it a Leap Year?

Happy Leap Day! Why would I be celebrating a leap day, you ask? Well, it only happens once every four years and it helps to align the seasonal year with the Gregorian calendar.

If we didn't add an extra day to February every fourth year, the calendar would eventually lose sync with the astrological cycle, according to the U.S. Naval Observatory.

If that were to happen, how would I know when to get my oxen into gear for the plowing season? I've got to plant my petunias. Fine, I don't have oxen, they don't have gears, I don't even know what or when a plowing season is and I'm pretty sure planting petunias doesn't require that much digging.

Google marked this occasion with a doodle of Italian composer Gioachino Rossini, who was born on a leap year. He composed his first piece at 4 years old and retired at 9. That's the life of a leap-yearer. Fast and hard. OK, in Gregorian years he was 18 when he composed his first piece and 37 when he retired. To be fair, he could only technically celebrate his birthday every four years, so you do the math.

If you're reading this after leap day, you can find the doodle in Google's 2012 doodle archive.