Yeah, I thought about that as I was writing my comment and realized that's why I always write "back to front dates" with dashes instead of slashes. I think it's probably because I always use that format in filenames and slashes feel like a very bad idea there ;-)
Yes, it would be so great if there could be a standard for dates formatted this way. It would have to be called something awesome like ISO 8601! ;-)
That is definitely also my preferred format, everything just sorts naturally then. Not so in love with the 2017-09-25T12:00 format as it does not work for filenames on my OS.
There definitely still is ambiguity if you're unfamiliar with the format. Show someone "2017-07-06" and they still might be unsure whether that's June or July.
I have never seen YYYY-DD-MM format, on the other hand, both DD/MM/YY and MM/DD/YY are equally common, that's why I always prefer YYYY-MM-DD format as it is the least ambiguous and most useful (sorting files etc., as other comments have mentioned). Feel free to prove me wrong though.
I work with non-techies. Most are totally unfamiliar with YYYY-MM-DD so weren't sure what a date that was ambiguous in that format was. I totally agree that usage of YYYY-DD-MM is rare (in my experience, anyway), but none of these formats fare particularly well when it comes to discoverability.
I’d update the Wikipedia article but don’t have time to go digging for official sources. Something you (or someone else with domain knowledge) could do?
I've been to Latvia many times in last few years, but haven't noticed YYYY-DD-MM format, maybe it's historical? It looks like DD.MM.YYYY was the most common format there (at least on posters).