Here is a collection of silly, strange and obscure unofficial holidays celebrated in December. Links in boldface are featured on Worldwide Weird Holidays.

December 1

Eat a Red Apple Day
International Sweater Vestival – 2017
Civil Air Patrol Day
Day Without Art
World AIDS Day

December 2

Rockefeller Center Christmas Tree Lighting – 2015
Business of Popping Corn Day
International Day for the Abolition of Slavery
National Fritters Day
National Mutt Day
Play Basketball Day
Safety Razor Day
Special Education Day

December 3

Chester Greenwood Day – 2016 – 1st Saturday
Make a Gift Day
International Day of Persons with Disabilities
National Apple Pie Day
National Green Bean Casserole Day
National Roof-Over-Your-Head Day
SKYWARN Recognition Day

December 4

Santa’s List Day
Extraordinary Work Team Recognition Day
National Cookie Day
National Dice Day
National Kitten Day
Wear Brown Shoes Day

December 5

Krampus
International Ninja Day
International Volunteer Day
National Communicate with Your Kids Day
National Commute with Your Baby Day
National Day of Solidarity
National Sachertorte Day
Repeal Day

December 6

Microwave Oven Day
Mitten Tree Day
National Miners Day
National Gazpacho Day
National Pawnbrokers Day
Put On Your Own Shoes Day
St. Nicholas Day

December 7

National Cotton Candy Day
International Civil Aviation Day
National Letter Writing Day
National Pearl Harbor Remembrance
Special Kids Day

December 8

Tió de Nadal begins
Take It in the Ear Day
National Brownie Day
National Christmas Tree Day
Pretend to be a Time Traveler Day

December 9

Cremation Day
Official Lost and Found Day – 2016 – 2nd Friday
Christmas Card Day
International Anti-Corruption Day
National Pastry Day
National Salesperson’s Day
Weary Willie Day
World Techno Day

December 10

Dewey Decimal Day
Festival for the Souls of Dead Whales Day
Human Rights Day
National Lager Day
Nobel Prize Day

December 11

Worldwide Candle Lighting – 2016 – 2nd Sunday
Holiday Food Drive for Needy Animals Day
International Mountain Day
National Noodle Ring Day

December 12

Poinsettia Day
Festival of Unmentionable Thoughts
Gingerbread House Day
National 12-Hour Fresh Breath Day
National Ambrosia Day
National Ding-a-Ling Day

December 13

National Day of the Horse
Ice Cream Day
National Cocoa Day
National Violins Day

December 14

Monkey Day
National Bouillabaisse Day

December 15

Cat Herders’ Day
National Regifting Day – 2016 – 3rd Thursday
Bill of Rights Day
National Lemon Cupcake Day

December 16

Boston Tea Party
National Ugly Christmas Sweater Day –  2016 – 3rd Friday
Barbie and Barney Backlash Day
National Chocolate Covered Anything Day
Stupid Toy Day
Underdog Day – 2016 – 3rd Friday

December 17

Wright Brothers Day
National Maple Syrup Day
Pan American Aviation Day

December 18

Bake Cookies Day
Flake Appreciation Day
Free Shipping Day
International Migrants Day
National Ham Salad Day
National Roast Suckling Pig Day
National Wear a Plunger on Your Head Day

December 19

National Oatmeal Muffin Day
Holly Day
Look for an Evergreen Day
National Hard Candy Day

December 20

Mudd Day
Cathode-Ray Tube Day
Dot Your I’s Day
Games Day
Go Caroling Day
International Human Solidarity Day
National Sangria Day
Sacagawea Day

December 21

Forefathers’ Day
Anne and Samantha Day
Crossword Puzzle Day
Humbug Day
National Flashlight Day
National French Fried Shrimp Day
National Kiwi Fruit Day
National Look At The Bright Side Day
Phileas Fogg Win a Wager Day
Winter Solstice – 2016 – longest day of year
Yule

December 22

National Cookie Exchange Day
National Date Nut Bread Day

December 23

Festivus
HumanLight
National Pfeffernuesse Day
National Roots Day

December 24

National Eggnog Day
Super Saturday – 2016 – last Saturday before Christmas
Last-Minute Shopper’s Day

December 25

A’phabet Day/No-L Day
National Pumpkin Pie Day

December 26

National Whiner’s Day
Boxing Day
Kwanzaa
National Candy Cane Day
National Thank You Note Day

December 27

National Fruitcake Day
Make Cut Out Snowflakes Day
Visit the Zoo Day

December 28

Pledge of Allegiance Day
Call a Friend Day
National Card Playing Day
National Chocolate Candy Day

December 29

National Pepper Pot Day
Tick Tock Day

December 30

National Bicarbonate of Soda Day
Bacon Day
Festival of Enormous Changes at the Last Minute

December 31

Banished Words List Day 2016
Banished Words List Day 2015
Make Up Your Mind Day
National Champagne Day
New Year’s Eve