December 11 Holidays & Observances
1 holiday observed on December 11 in the 2026–2030 window.
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See every observance across December in one monthly calendar.
December calendar →December 11 — quick answers
- How many holidays fall on December 11?
- In the 2026–2030 window, 1 holiday and observance falls on December 11: International Mountain Day.
- What is celebrated on December 11?
- December 11 is home to International Mountain Day. Each one has its own page with history and a live countdown.
- Are any December 11 holidays public holidays?
- None of the observances on December 11 are US federal holidays; they are celebrated informally by people, brands and communities.