in the insert record behavior, when you bind the date column to the date form element, it will generate code like this:
<?php echo((isset($_POST["dateField"]))?$_POST["dateField"]:"") ?>
you will need to use the strtotime() and date() functions to convert the date format to thewhat is expected by the database:
<?php echo((isset($_POST["dateField"]))?date("Y-m-d h:m:s", strtotime($_POST["dateField"])):"") ?>