2 observances land on 31 December. We have not found a recorded founder for any of them.
| Observance | Declared by | First year | Source |
|---|---|---|---|
| International Solidarity Day of Azerbaijanis Azerbaijan | no record | — | — |
| The sixth and penultimate day of Kwanzaa United States | 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 31 December here. The next one is Thursday, 31 December 2026.
Thursday, 31 December 2026 has no name yet. It costs $2.