Well, you should've used your DBMS's own date/time types to store dates 😃 Or at the very least use an unambiguous format, like some subset of ISO8601 (i.e., yyyy-mm-dd).
Consider strtotime('08/12/2004'). How is that date to be interpreted? 12th August or 8th December? The third alternative is to just give up and complain that it's unparseable, but strtotime was written by Americans.
If you don't want to use explode(), consider using sscanf().