how well-developed a standard format is (with respect to useful properties)
dafaq?
Only use I can think of is sorting out files. Indeed, YYYY-MM-DD is the most useful in this case, but is that it?
In Australia, we just say from the mose precise to the least precise details, such as "It is now 9:23, on the Thirteenth of February, 1992" while lil'mericans or whatever use "It is now 9:23 AM, February the thirteenth, 1992" but for business efficency in terms of sorting, it's just the reverse of the Australian Standards: "It is 1992, February the thirteenth, 09:23."
However, I've never seen "13.02.92" written in my country (as assumed by the wiki,) we use the latter example they provided ("13/2/92" without prefixed '0's unless entering into a database).
One annoying thing though, is that practically 99% of our computers use american standards by default (without any other options for most cases), so when viewing files by date, I'm still not used to searching for the middle column for date.