$time = new DateTime('00:00:00');
$fulltime = clone $time;
$time->add($counttimethere);
$time->add($counttimeback);
echo 'Общее время:' . $fulltime->diff($time)->format("%H:%I:%S");$dtz = new DateTimeZone('America/Los_Angeles');
$zona = new DateTime('now', $dtz);
$offset = $dtz->getOffset($zona) / 3600;
echo "GMT" . ($offset < 0 ? $offset : "+".$offset);$target_time_zone = new DateTimeZone('America/Los_Angeles');
$date_time = new DateTime('now', $target_time_zone);
echo 'GMT '.$date_time->format('P');