True, but it is a difference between how you say something and how you write it. The spoken variant will automatically clairify wether you use month or day first. Like "January first" or "1st of January". But in written anything but the ISO-standard is ambigious, unless you really spell everything out as for example "January 1st, 2001".
But with the short-format with just AA-BB-CC you have absouletely no idea if it is YY-MM-DD, DD-MM-YY or MM-DD-YY. so for stuff like food or medicine or other stuff that are perishable that can be dangerous...
Here in Sweden we used the ISO-standard, before we joined the EU. Sadly the EU incorrectly uses the format DD-MM-YY. I blame the Germans for that.