Re: It depends on what you mean
"I use the East-Asian format (YYYY-MM-DD) as a matter of course and it does not go down well in Europe. "
In the 1970s that style was already the established standard in Scandinavian countries. It is the human readable form of the ISO order with separators. I have used that field order in the UK as yyyy/mm/dd for over 40 years.
I have an application that recognises dates in web postings from many countries. It currently runs to about ten major processing variations - some of which have several minor variations. That excludes language conjugation variations for months.