An imaginary day created by the Easter Bunny. There are so many great things about this day. Now, for one it's Februaury, which never goes past 29 days. Most months only go up to 31 days, so "32nd" would sound a bit more obvious. Something about 33rd makes it sound more like a real day. Think about it. If you heard a movie trailer that said "February 33rd" you wouldn't think twice about.
Wit' 'dis giant Easta' egg bomb, I'm-a blow ya' to 'de imaginary day of February 33, in which you'll be trapt' fo' all eternity.