Today is Leap Day. Here are a few facts about Leap Year, in case you were wondering. 

Leap Year happens every four years, but there is one exception. Years ending in double zeros are not, like 1900 and 2100. But, according to Geoff Chester from the United States Naval Observatory there is one exception to that exception. Years ending in double zeros that can be evenly divided by 400 such as 1600 and 2000 are in fact Leap years. Confused yet?

So, why do Leap Years exist? Blame the ancient Egyptians. They were the ones that first figured out that the solar year and the man made calendar didn't quite jive. That's because it takes the Earth a little longer than a year to travel to travel around the sun. To be exact, Earth's orbit is 365 days, five hours, 48 minutes and 46 seconds so as the hours accumulated over the centuries, one extra day was added to the calendar and over time, it became official.

Not to just throw the Egyptians under the bus, it was the Romans that first designated February 29 as Leap Day, but there was a precise formula adopted in the 16th Century when the Gregorian calendar really fine tuned the calculations to include one extra day in years divisible by four.

The odds of having a birthday on February 29 are about one in 1,461 and there are about four million people in the world who have a birthday on Leap Day. So, if you were born on Leap Day, when do you celebrate your birthday? February 28 or March 1? About 80 percent of people who have a Leap Day birthday choose to celebrate it on February 28 in non-Leap Years.