I think I see what you are saying, when you setup your table field, set the number to:
month int(2) NOT NULL UNSIGNED ZEROFILL
day int(2) NOT NULL UNSIGNED ZEROFILL
year int(2) NOT NULL UNSIGNED ZEROFILL
You can use this type for sorting and for display.
$sql = mysql_query("SELECT * FROM tablename ORDER BY year DESC,month DESC,day DESC") or die (mysql_error());
This will list newest to oldest.