month-first or month-last doesn't matter, until you add more time periods. YY/MM/DD and DD/MM/YY are both fine, but MM/DD/YY is braindead. Month-first gains the

month-first or month-last doesn't matter, until you add more time periods. YY/MM/DD and DD/MM/YY are both fine, but MM/DD/YY is braindead. Month-first gains the edge, though, when you add time-of-day, since no-one does ss/mm/hh