Suggestion for problem resolution.

Create a function in date_api.php for example:

/**

• Get the date in integer representation
• @param string $p_datetime
• @return int date
• @access public
  */
  function date_to_time( $p_datetime ) {
  $value = $p_datetime;
  if ( strpos( $value, '/' ) == 2 ) {
  $vlist = explode( ' ', $value );
  $vdate = explode( '/', $vlist[0] );
  $vtime = explode( ':', $vlist[1] );
  $value = mktime( $vtime[0], $vtime[1], 0, $vdate[1], $vdate[0], $vdate[2] );
  }
  else {
  $value = strtotime( $value );
  }
  return $value;
  }

Call date_to_time() in substitution strtotime().