- December 1 Eat a Red Apple Day
- December 2 National Fritters Day
- December 3 National Roof over Your Head Day
- December 4 Wear Brown Shoes Day
- December 5 Bathtub Party Day
- December 7 Letter Writing Day
- December 7 National Cotton Candy Day
- December 8 National Brownie Day
- December 9 Christmas Card Day
- December 9 National Pastry Day
- December 11 National Noodle Ring Day
- December 12 National Ding-a-Ling Day
- December 12 Poinsettia Day
- December 13 Violin Day
- December 16 National Chocolate Covered Anything Day
- December 18 Bake Cookies Day
- December 19 Look for an Evergreen Day
- December 20 Go Caroling Day
- December 21 Humbug Day
- December 21 National Flashlight Day
- December 21 Look on the Bright Side Day
- December 22 Winter Solstice
- December 23 Festivus - for the rest of us
- December 26 Boxing Day
- December 27 National Fruitcake Day
- December 28 Card Playing Day
- December 30 National Bicarbonate of Soda Day
- December 31 Make Up Your Mind Day
