I know that Americans use MM/DD/YYYY. But YYYY-DD-MM???

Time goes from the largest to the smallest: hours, minutes, seconds. And the same applies to date: years, months, days.

I've certainly seen things like "ten past four" written, and it's commonly spoken, but so are "four ten" and "sixteen ten".

But the date is most commonly spoken in Europe (including in Britain and Ireland) in the form "twelfth of August, twenty twenty-two", so 12/8/2022 (the most common date format in UK/IE) follows from that.