| December Monthly Observances |
| Bingo's Birthday Month |
| Colorectal Cancer Education and Awareness Month |
| Identity Theft Prevention and Awareness Month |
| National Drunk & Drugged Driving (3D) Prevention Month |
| Choose A Summer Camp Month |
| National Write A Business Plan Month |
| National Tie Month |
| Safe Toys and Gifts Month |
| Spiritual Literacy Month |
| Take a New Year's Resolution to Stop Smoking (TANYRSS) (12/1 - 2/11) |
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| December Weekly Observances |
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| Chanukah (Hanukkah): 22-29 |
| National Aplastic Anemia Awareness Week: 1-7 |
| Recipe Greetings For The Holidays Week: 1-8 |
| Operation Santa Paws Week: 1-22 |
| National Handwashing Awareness Week: 7-13 |
| Clerc-Gallaudet Week: 7-15 |
| Human Rights Week: 10-17 |
| Gluten-free Baking Week: 14-20 |
| Posadas: 16-24 |
| It's About Time Week: 25-31 |
| Kwanzaa: 26-1/1 |
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| December Daily Observances |
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| Bifocals at the Monitor Liberation Day: 1 |
| Day With(out) Art Day: 1 |
| International Voluntary HIV Counselling & Testing Day: 1 |
| World Aids Day: 1 |
| International Day for the Abolition of Slavery Day: 2 |
| Rockerfeller Center Xmas Tree Lighting: 2 |
| Special Education Day: 2 |
| Special Kids Day: 3 |
| International Day of Disabled Persons: 3 |
| Chase's Calendar of Events Birthday: 4 |
| Extraordinary Work Team Recognition Day: 4 |
| National Dice Day: 4 |
| AFL-CIO Day: 5 |
| Bathtub Party Day: 5 |
| International Volunteer Day for Economic & Social Development: 5 |
| Coats & Toys for Kids Day: 6 |
| Miners' Day: 6 |
| National Pawnbrokers Day: 6 |
| Skywarn Recognition Day: 6 (First Saturday in December) |
| National Pearl Harbor Remembrance Day: 7 |
| International Civil Aviation Day: 7 |
| National Cotton Candy Day: 7 |
| Eid-ul-Adha: 8 |
| Weary Willie Day: 9 |
| Human Rights Day: 10 |
| International Mountain Day: 11 |
| UNICEF Birthday: 11 |
| Poinsettia Day: 12 |
| International Shareware Day: 13 |
| Day Of The Horse: 13 |
| National Childrens' Memorial Day: 14 |
| Bill of Rights Day: 15 |
| Cat Herders Day: 15 |
| Barbie and Barney Backlash Day: 16 |
| National Chocolate-covered Anything Day: 16 |
| Clean Air Day: 17 |
| Wright Brothers Day: 17 |
| International Migrants Day: 18 |
| Day for South-South Cooperation: 19 |
| Underdog Day: 19 |
| International Human Solidarity Day: 20 |
| Sacagawea Day: 20 |
| Mudd Day: 20 |
| Forefathers Day: 21 |
| Hanukkah: 21 |
| Humbug Day: 21 |
| Phileas Fogg Win A Wager Day: 21 |
| National Haiku Poetry Day: 21 |
| World Peace Day/Winter Solstice: 21 |
| Festivus: 23 |
| A'Phabet Day or No "L" Day : 25 |
| Christmas: 25 |
| Boxing Day: 26 (Canada) |
| National Candy Cane Day: 26 |
| National Whiner's Day: 26 |
| National Chocolate Day: 28 & 29 |
| Islamic New Year: 29 |
| Tick Tock Day: 29 |
| Falling Needles Family Fest Day: 30 |
| Make Up Your Mind Day: 31 |
| New Years Eve: 31 |
| No Interruptions Day: 31 |
| Universal Hour of Peace Day: 31 |
| World Peace Meditation Day: 31 |
