What happened to flags on 13 April
2 flags in the atlas carry this date. The sentence under each one is where that is written down, in its own article.
- Russia 1918
On 13 April 1918, the All-Russian Central Executive Committee established the RSFSR flag to be a red banner with the inscription Russian Socialist Federative Soviet Republic.
From Flag of Russia on Wikipedia, as it read on 2026-08-29
- India 1923
On 13 April 1923, during a procession by local Congress volunteers in Nagpur commemorating the Jallianwala Bagh massacre, the Swaraj flag with the spinning wheel, designed by Pingali Venkayya, was hoisted.
From Flag of India 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.