5 observances land on 3 October. We have not found a recorded founder for 4 of them.
| Observance | Declared by | First year | Source |
|---|---|---|---|
| Mean Girls Day worldwideit alludes to a line by Cady in the 2004 film, and Paramount streamed the film free on TikTok for it in 2023 | fans on social media | 2012 | Wikipedia |
| 3 October Festival Leiden, NetherlandsWikipedia says it was made a city holiday in 1886 | no record | 1575 | Wikipedia |
| German Unity Day Germany | no record | — | — |
| Morazán Day Honduras | no record | — | — |
| National Foundation Day or Gaecheonjeol South Korea | 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 3 October here. The next one is Sunday, 3 October 2027.
Sunday, 3 October 2027 has no name yet. It costs $2.