format('Y-m-d H:i:sP') . "\n";

$date->setTimezone(new DateTimeZone('Pacific/Chatham'));
echo $date->format('Y-m-d H:i:sP') . "\n";
?>
  
  2000-01-01 00:00:00+12:00
2000-01-01 01:45:00+13:45