I sure as hell won't accept American month-day-year - sorry guys, but that's just dumb.
Not to get overly technical, but that's dependent on the country you live in.
Here in Canada (and I'm assuming the States as well), we write our date (using today's as an example) "November 23, 2007". Broken down, that's "November(MM) 23(DD), 2007(YYYY)", the MM-DD-YYYY notation. However I do know of people (and I'm sure countries by standard) that write the date as "23 November, 2007", which follows the DD-MM-YYYY notation. As for YYYY-MM-DD notation, it makes no sense to me because I've never seen anybody write the date "2007, November 23", but I could have missed something.
As a side note, writing the year as 0820 is a totally unrelated thing, considering you're breaking up a number to do that (which in turn would be the same concept as November 23 being mberNove 32 instead), unless there's a language convention at play there, in which case I have nothing to say on the topic.
In any case, straying from the technical point of view, I use DD-MM-YYYY because it's what I'm used to.