3 observances land on 31 May. We have not found a recorded founder for any of them.
| Observance | Declared by | First year | Source |
|---|---|---|---|
| Anniversary of Royal Brunei Malay Regiment Brunei | no record | — | — |
| World No Tobacco Day International | no record | — | — |
| Borobi Day Australia | 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 May here. The next one is Monday, 31 May 2027.
Monday, 31 May 2027 has no name yet. It costs $2.