March 14. (3.14)
What? I celebrate all holidays: Christian, Catholic, Jewish, American, French, Mexican, Irish, and even Nerd. I feel the least amount of guilt with the Nerd Holidays. Except maybe I feel a bit of guilt that I am not nerdy enough. I mean, can anyone really ever be nerdy enough?
What do you do on Pi Day?
You eat pie, of course. Chicken Pot Pie for dinner with pie for dessert. Maybe even a pie game. And try to say "pi" and "3.14159" as often as you can. For the truly nerdy, try to memorize even MORE numbers of pi (go here if you're interested). Also, watch movies about pi.
See? So much fun.