What happened to flags on 4 April
3 flags in the atlas carry this date. The sentence under each one is where that is written down, in its own article.
- Mali 1959
The original flag was adopted on 4 April 1959, when Mali joined the Mali Federation.
From Flag of Mali on Wikipedia, as it read on 2026-08-26
- Senegal 1959
Senegal was combined with French Sudan on April 4, 1959, to form the Mali Federation.
From Flag of Senegal on Wikipedia, as it read on 2026-08-26
- Hong Kong 1990
The original design of the flag of Hong Kong was unveiled on 4 April 1990 at the Third Session of the Seventh National People's Congress.
From Flag of Hong Kong 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.