5 observances land on 11 December. We have not found a recorded founder for any of them.
| Observance | Declared by | First year | Source |
|---|---|---|---|
| Establishment of Kurdish Women's Union Iraqi Kurdistan | no record | — | — |
| Indiana Day United States | no record | — | — |
| International Mountain Day | no record | — | — |
| National Tango Day Argentina | no record | — | — |
| Pampanga Day Pampanga province, Philippines | no record | — | — |
"No record" means we could not find one, not that none exists. Where a founder is named, the source is named with it.
Who decides these? Nobody official. A brand, a trade body, a government, or one person with a website. Most are simply asserted and then repeated until they look official. Here, whoever names it first.
Nobody has ever named 11 December here. The next one is Friday, 11 December 2026.
Friday, 11 December 2026 has no name yet. It costs $2.