Math Geeks Celebrate Square Root Day

Odds are you’re not aware of it, but today is a major holiday. Well, major for math teachers and their lucky students. It's Square Root Day, a super-rare, super-goofy holiday that occurs whenever the first two digits of the date—in this case 3/3—can be multiplied to form the last two digits of the year.

These “calendar comets,” as one teacher colorfully dubbed them, come around only nine times a century—the last one was Feb. 2, 2004. Extra points for any commenter who can come up with the next one (and no cheating by looking at the sources). Celebrants commemorate the big day by chopping root vegetables into squares. (More mathematics stories.)