At Hampshire College in the early 1960s, two mathematicians, David Kelly and Michael Spivak created a brand new holiday: Yellow Pigs Day, or Yellow Pigs Math Day, depending on who you ask.
What is Yellow Pigs Day? Well, it celebrates math, the number seventeen, and the mythical yellow pig, a remarkable animal with seventeen eyelashes.
If you ask me, this holiday has more in common with an inside joke than anything else! Nevertheless, Yellow Pigs Day is the time to make math jokes, attempt difficult math problems, sing Yellow Pig songs, give mathematical or porcine gifts, and even (according to wikipedia) playing Ultimate. Have fun!
“Teach us to number our days aright,
that we may gain a heart of wisdom.”