Most people know that a leap year is every four years and that it has something to do with the Earth circling the sun. But many may not be aware of the purpose of this extra day – and may know even less about how it came to be. The story is complex and it goes back to ancient Roman times. Over the centuries, February 29 has prompted some unusual customs, wild rumors and strange superstitions.
A year is actually longer than 365 days
It's all about the sun! We grew up being told the Earth takes 365 days to make a complete circle around the Sun, but it actually takes 365 days, 5 hours, 48 minutes and 45 seconds – or 365.24219 days. An extra day is added about every four years as a corrective measure to stay in sync with the solar year.