Has far as I know the date format isn't flexible.
There is however nothing stopping you from moving the value of the date around to record and show them the way you want.
have a look there:
http://uk2.php.net/substr
$date="1977-01-09";
$date=substr($date,5,5)."-".substr($date,0,4);
might not be totaly exact but thats the idea...
I hope you find that usefull.