Receive Date is Missing on Contribution Thank-you Page and Receipt

Using PayPal Pro - test-drive with either of the two sample contribution pages... on success, the Thank-you page and the Receipt are supposed to display the Receive Date ($receive_date var). But both are empty (including empty when I added

{debug}

to the receipt output).

The receive_date IS being saved to the contribution DB record properly however.

CRM/Contribute/Form/Contribution/ThankYou.php seems to be assigning the value from params, but evidently it doesn't exist in params at that point or ???

line 133:
$this->assign( 'receive_date',
CRM_Utils_Date::mysqlToIso( $this->_params['receive_date'] ) );