Annual No Pants Day First Friday in May 5/1/09

{Okay, I think I just found my favorite new holiday! You girls, no cheating and wearing skirts!}
What in the world is No Pants Day?
No Pants Day is a day where everyone, be they students, respectable businessmen, or cherished community leaders, leave their pants behind. Usually this means wearing thick, appropriately modest boxer shorts, but bloomers, slips, briefs, and boxer-briefs all work as well.

Their website is a bit out of date!