What happened to flags on 20 May
4 flags in the atlas carry this date. The sentence under each one is where that is written down, in its own article.
- Cuba 1902
It was designed in 1849 and officially adopted May 20, 1902.
From Flag of Cuba on Wikipedia, as it read on 2026-08-26
- Sudan 1970
The flag of Sudan (عَلَم السُّودَان) used since 20 May 1970 consists of a horizontal red-white-black tricolour with a green triangle at the hoist.
From Flag of Sudan on Wikipedia, as it read on 2026-08-26
- Cameroon 1975
This flag was originally adopted on 26 October 1957 as a plain tricolor then gained its present form on 20 May 1975 after Cameroon became a unitary state.
From Flag of Cameroon on Wikipedia, as it read on 2026-08-26
- Bosnia and Herzegovina 1992
Initially, the newly independent Republic of Bosnia and Herzegovina continued to use the flag of the Socialist Republic of Bosnia and Herzegovina until a new flag was adopted on 20 May 1992.
From Flag of Bosnia and Herzegovina on Wikipedia, as it read on 2026-08-29
How a day gets onto this site
A flag is here because a sentence in its own English Wikipedia article puts it on this date, and that sentence is printed above. Nothing was worked out from a year, and nothing was written for the occasion. Every sentence names the article it came from and the version of that article it was read in, so you can go and check it.
The calendar is still short rather than full. A third of the year has no page here, because a flag only gets a day when a sentence in its article puts something on one, and plenty of articles never do. Nothing is invented to fill the gap.