So what is a leap year, and why do we have it? To find out I went to my favorite website of all time, Wikipedia.org, and found the following:
A leap year is a year containing one extra day in order to keep the calendar year synchronized with the astronomical or seasonal year. Because seasons and astronomical events do not repeat at an exact number of full days, a calendar which had the same number of days in each year would, over time, drift. By occasionally inserting an additional day or month into the year, the drift can be corrected. A leap year occurs once every four years; an easy way to remember is that the Summer Olympic Games always occur during leap year.
I also found out about a tradition that exists on the extra day during leap year: women may propose marriage. Supposedly, way back in the day, men who refused marriage proposals from women had to compensate them to “soften the blow,” and compensation could range from a kiss on the cheek or a new silk gown. Men felt that this law put them at too great a risk, so a new tradition was formed restricting female proposals to the modern leap day, 29 February. I've never heard of this "tradition" but it is interesting. I thought Wikipedia was making this up until I found a postcard from 1908 for leap day.