mngluser.php

    $date_format = __('F j, Y', 'mingle');

    $birthday_timestamp = (int)$this->_get_metadata( 'mngl_birthday' );
    if(isset($birthday_timestamp) and !empty($birthday_timestamp) and $birthday_timestamp)
      $this->birthday = date( $date_format, $birthday_timestamp );
    else
      $this->birthday = '';