Yes, It was the date format. It has to be yyyy-mm-dd for mySql.
The $date = date('Y-m-d', strtotime($date_entered)); doesn't work. This works for dates going into oracle, which I'm more familiar with, but something about mySql doesn't like it.
I used:
list($month, $day, $year) = explode("/", $date_entered);
$date_entered = "$year-$month-$day";
That did the trick.
Thanks to all for your help.