Yesterday, on 10/23, from 6:02 a.m. to 6:02 p.m., high school chemistry teachers across the country celebrated National Mole Day. They even had a theme song: "Mole Madness."
link to story:
http://www.npr.org/templates/story/story.php?storyId=6355951 In finding the link to the online article, I came across the "suggested links," wherein I saw a story regarding March 14, which is, apparently, National Pi Celebration day.
If only there were some clever date to put some sort of Literature-based holiday. Alas...