🌿 Nature & Environment
International Mountain Day
Dec 11
International Mountain Day on December 11 highlights why mountains matter for water, climate, biodiversity and the people who live there.
December 11, 2026: National Days & Holidays
December 11 is International Mountain Day, plus 2 more. Here’s everything celebrated on this date.
3observances on this date
345thday of 2026 (out of 365)
20days left in 2026
🔬 Science & Technology
National App Day
Dec 11
National App Day on December 11 celebrates the mobile apps we use every day. Learn the history of app stores, fun facts…
🤝 Awareness & Causes
UNICEF Day
Dec 11
UNICEF Day on December 11 marks the founding of the UN children's agency in 1946. Learn UNICEF's history, its work today and…
Weekly observances on December 11
4 week-long observances include December 11, 2026.
National Handwashing Awareness Week comes each December. Learn who started it, the four principles of hand awareness and how much clean hands cut illness.
About National Handwashing Awareness WeekComputer Science Education Week falls each December around Grace Hopper's birthday. Learn its 2009 origin, the Hour of Code and ways classes take part.
About Computer Science Education WeekNational Influenza Vaccination Week comes each December. Learn why CDC started it in 2005, who should get a flu shot and what the 2024–25 season showed.
About National Influenza Vaccination WeekHuman Rights Week begins on December 10 each year. See how it links the 1948 Universal Declaration with the Bill of Rights, ratified December 15, 1791.
About Human Rights WeekDecember 11 at a glance
- What national days are on December 11, 2026?
- December 11, 2026 has 3 observances: International Mountain Day, National App Day and UNICEF Day.
- Which weekly observances include December 11, 2026?
- December 11, 2026 falls during National Handwashing Awareness Week (Dec 6–12), Computer Science Education Week (Dec 7–13), National Influenza Vaccination Week (Dec 7–11) and Human Rights Week (Dec 10–16).
- What day of the year is December 11?
- December 11 is the 345th day of 2026, out of 365 days.
- How many days are left in the year after December 11?
- There are 20 days left in 2026 after December 11.
- What day of the week is December 11, 2026?
- December 11, 2026 falls on a Friday.
Key dates in December 2026
More in December
December 2026
SunMonTueWedThuFriSat1World AIDS DayRosa Parks Day+12National Mutt DayNational Special Education Day+13International Day of Persons with DisabilitiesNational Roof Over Your Head Day+14National Cookie DayNational Sock Day+15International Volunteer DayWorld Soil Day+16St. Nicholas DayNational Miners Day+17National Pearl Harbor Remembrance DayNational Cotton Candy Day+18Feast of the Immaculate ConceptionBodhi Day+19National Pastry DayNational Llama Day+110Human Rights DayDewey Decimal System Day+111International Mountain DayNational App Day+112Feast of Our Lady of GuadalupeNational Gingerbread House Day+113St. Lucia DayNational Cocoa Day+114Monkey DayNational Bouillabaisse Day+115International Tea DayBill of Rights Day+116Las Posadas (begins)Boston Tea Party Day+117SaturnaliaNational Maple Syrup Day+118National Twin DayNational Ugly Christmas Sweater Day+219National Emo DayNational Hard Candy Day+120National Sangria DayInternational Human Solidarity Day+121Winter SolsticeYule+222Forefathers’ DayNational Short Girl Appreciation Day+123FestivusNational Pfeffernüsse Day+124Christmas EveFeast of the Seven Fishes+125Christmas DayNational Pumpkin Pie Day+126Kwanzaa (begins)Boxing Day+227National Fruitcake DayInternational Day of Epidemic Preparedness+128Holy Innocents’ DayPledge of Allegiance Day+129Tick Tock DayNational Pepper Pot Day+130National Bacon DayNational Bicarbonate of Soda Day+131New Year’s EveHogmanay+1