BAO payment add is allowing day ofthe wrong type

When one passes data of the wrong type into the CRM_Pledge_BAO_Payment::add method, the incorrect data is not caught and is passed to the db

Exampe: the following call will attempt to pass the word 'Test' into the reminder_date field of the civicrm_pledge_payment table.
$params = array('pledge_id' => 1,
'scheduled_amount' => '100',
'scheduled_date' => date('Ymd'),
'reminder_date' => 'Test',
);
$paymentid = CRM_Pledge_BAO_Payment::add($params);