Leap year only comes around every 4 years, and is probably the least celebrated calendar-ish anomaly ever. Because, let's face it, it's just like any other day. But it used to hold a small amount of significance, and in case you're ever asked this question on Jeopardy, here's a tidbit of info about Leap Year:
Sometime in the 5th-ish century St. Bridget was the head of some nuns, and she was upset because these nuns were never getting marriage proposals (this was before nuns were celibate). So she asked St. Patrick if there could be a time when women could propose to men.
And St. Patrick said, "Sure, how about every 7 years?"
And St. Bridget said, "No, how about every 4 years?"
And then he said, "Ok, that sounds fair."
And then she said, "Ok. Will you marry me?"
And he said, "Uh, no. But I'll buy you a silk gown and give you a kiss instead."
So after that, in the British Isles during the Middle Ages, there was an unwritten law that said a woman could propose marriage to a man anytime during Leap Year. And if that man refused her, he was required to buy her a nice dress and give her a kiss. So sometimes, February 29th is referred to as "Ladies Day".
And I'm thinking, if that tradition still existed back when I was single, I would have been proposing right and left during Leap Year just so I could replace my entire wardrobe for free.
So let's celebrate Leap Day this year - go make a man buy you something nice!