National Punctuation Day comes around every September 24. It even has its own website (www.nationalpunctuationday.com) and everything! If you have some time to spare, click over there and check out some of the links and resources. It's grammar-geek heaven.
As you can tell by the time stamp on this post, I almost missed the festivities. That's what happens when life gets in the way of writing. If you hurry, you can still get cake and balloons and celebrate those funny little marks that spend the rest of the year being misused or ignored.