2 observances land on 10 June. We have not found a recorded founder for any of them.
| Observance | Declared by | First year | Source |
|---|---|---|---|
| World Art Nouveau Day Worldwide | no record | — | — |
| Portugal Day, also Day of Camões Portugal and the Portuguese communities | 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 10 June here. The next one is Thursday, 10 June 2027.
Thursday, 10 June 2027 has no name yet. It costs $2.