- If your MySQL column is DATE type:
$date = date('Y-m-d', strtotime(str_replace('-', '/', $date)));
- If your MySQL column is DATETIME type:
$date = date('Y-m-d H:i:s', strtotime(str_replace('-', '/', $date)));
You haven't got to work strototime(), because it will not work with dash - separators, it will try to do a subtraction.
Update, the way your date is formatted you can't use strtotime(), use this code instead:
$date = '02/07/2009 00:07:00';
$date = preg_replace('#(\d{2})/(\d{2})/(\d{4})\s(.*)#', '$3-$2-$1 $4', $date);
echo $date;
Output:
2009-07-02 00:07:00