Why Does There Need To Be a Leap Day?

 Once every four years, February gets an extra day. We call it Leap Day, and "Leap Day babies" get to celebrate their real birthday. But many people aren't aware of why February 29th is necessary.

A year is defined as the time it takes the earth to circle around the sun. We need Leap Days because it takes the Earth slightly longer than 365 days to make the circuit.  It actually takes 365 days, five hours, 48 minutes and 45 seconds. 

So without Leap Years, we'd be off by about six hours every year.  That doesn't sound like much, but over 100 years, it adds up to nearly 25 whole days.

Leap Day was tacked on to February because centuries ago, that was the final month of the ancient Roman calendar, which saw March and spring as the beginning of each year.

(In addition to Leap Days and Leap Years, there's also a Leap Second. The last one was added on December 31st, 2016, and the next one might be added on December 31st of this year.)

Less than 0.07% of the world's population is estimated to have been born on February 29th . That means among America's population of more than 320 million, only about 205,000 people have a birthday today.  (Or about 4.8 million people in the whole world.) Dinah Shore is among history's more well-know leap babies.

Some unique traditions involve Leap Day. In fifth-century Ireland, legend has it that St. Patrick blessed a law that every February 29th, women were allowed to propose marriage, and men who said no had to pay a fine.
An American offshoot of the role-reversing tradition is Sadie Hawkins Day, created in the 1930s by cartoonist Al Capp in his strip "Lil' Abner." Sadie Hawkins Day was when the unmarried women could chase, catch and marry the men of Dogpatch. The concept was adapted in real life as Sadie Hawkins dances where women invited the man of her choice, instead of waiting to be invited. Many schools eventually adopted Leap Day as the day that the dance was held.

The comic strip was discontinued in 1978, but Sadie Hawkins dances still take place in many locations in the U.S. and Canada.