What happened to flags on 19 April
2 flags in the atlas carry this date. The sentence under each one is where that is written down, in its own article.
- Sweden 1562
The oldest recorded pictures of a blue cloth with a yellow cross date from the early 16th century, during the reign of King Gustav I. The first legal description of the flag was made in a royal warrant of 19 April 1562 as: "yellow in a cross fashioned on blue" (gult udi korssvijs fördeelt påå blott).
From Flag of Sweden on Wikipedia, as it read on 2026-08-29
- Cape Verde 1976
The first Cape Verdean national flag was hoisted the same day the country became independent, but it was not until 19 April 1976 that the flag became official by law.
From Flag of Cape Verde on Wikipedia, as it read on 2026-08-26
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.