I’ve bookmarked the direct link to this before, but I like Paper Forest’s writeup on this item, and it’s certainly a site worth checking out if you’re into papercraft and paper art things.

In case you’re one of the 3 people left on the planet who hasn’t been exposed to this meme ad-infinitum!

http://paperforest.blogspot.com/2006/01/12-sided-calendar.html