EDIT: Okay, third edit. I think I got it right this time
Its not "a bunch of Americans", that is the ISO date standard format.
Oh sorry, I meant MM-DD-YYYY. I don't know why I put the standard one in.
do they want it as an option or as the default? That option is a default one in the UserCP > Edit Options > Date and Time Options
if you want to set the default, just change the Date format setting in the ACP to "m-d-Y"
Strange. One of my users was insisting he couldn't see it. I'm going to have to follow up on this. Cheers.
EDIT: No, wait, he was talking about YYYY-MM-DD being unavailable (his post was worded strangely). That's the one not in the list. The ACP suggestion worked, though.