YYYY-MM-DD is also the official date format in Canada, though it's not officially enforced, so outside of government documents you end up seeing a bit of all three formats all over the place. I've always used ISO 8601 and no one bats an eye, and it's convenient since YYYY-DD-MM isn't really a thing, so it can't be confused for anything else, unlike the other two formats.

YMD has caught on, I think, because it allows for the numbers to be "in order" (not mixed-endian) while still having the month before the day which matches the practice for speaking dates in (at least) the US and Canada.

8601, when used fully according to spec sucks. It makes today 20250902. It doesn't have seperators. And for adding a time it gets even less readable.

Its a serialization and machine communication format. And that makes me sad. Because YYYY-MM-DD is a great format, without a good name.

I always like the compromise of the M/D/M system popularised by the British documentary series Look Around You, e.g. "January the fourth of March".

I live in that country, and I am constantly messing up date forms. My brain always goes yyyy-mm-dd. If I write it out, September 1st, 2025, I get it in the “right” order. But otherwise, especially if I’m tired, it’s always in a sortable format.