Thanks for the reply.
Unfortunately, it's still not working. I was thinking whether it might have anything to do with how I constructed "2004-06-12",
$currentDate = mktime (0,0,0,date("m"), date("d"), date("Y"));
$dateToday = date("Y-m-d", $currentDate);
I then stored $dateToday in field with DATE format. Grasping at straws? It's all I can think of!