Hold on...moldy cheese? There's a celebration for that? Well, jeez, if I had known, I wouldn't have kept on throwing out the darn stuff when the fuzz showed up. (I'm referring to cheese and mold, of course, not "stuff" and, ahem, law enforcement...)
Here's the real deal: Moldy Cheese Day is set aside to celebrate those cheeses that are supposed to be moldy. Bleu. Camembert. Gorgonzola. Maytag Blue (the cheese - yes, it's really a cheese - not the washing machine). Roquefort (the cheese - not the little mouse from The Aristocats). Brie (the cheese - not the Desperate Housewife). Stilton (the cheese - not the children's chapter book character).
So, on October 9th, take a gander in your fridge. If you find some regular cheese in there that's a bit furry, throw it out! But, if you have some of the "on purpose" moldy cheese, then by all means, set it out with some crackers, and join the celebration.
Places to read about cheese (moldy or otherwise):