Took me a while, then realised there is a country that uses whack date formatting. dd/mm/yyyy is the true king. All others shall bow.
IMO it's actually the best for everything. dd/mm/yyyy is ambiguous due to the American date format existing.
What does American date formatting have to do with anything / anyone outside of America?
DMY is the perfect progression. 2nd of the 3rd, 23. Perfect sense logically speaking.
What does American date formatting have to do with anything / anyone outside of America?
If you see a date somewhere, you can't ever be 100% sure that it's dd/mm/yyyy, as an American may have written it. On the other hand, yyyy-mm-dd is unambiguous.
DMY is the perfect progression.
That's not the case when written with a time next to it, because in that case it's inconsistent and "backwards" compared to the time. The date goes from "smallest" unit (day) to largest unit (year), yet time is written the opposite way, with the largest unit (hour) to the smallest unit (seconds or milliseconds). If you instead do yyyy-mm-dd hh:mm:ss, the entire thing is in a consistent order.
In the US, it's still Thursday Oct. 5th (10/05) right now as I write this. So yesterday was Wednesday October 4, which could be written as 10-4, which as another comment pointed out is a code well known in popular culture meaning roughly "yes". ("Acknowledged")
No, assuming year first it's already in the right order for ISO 8601
They likely live outside the US, somewhere where it's already Friday, so "no" is just the answer to the question for them.