timestamp.setTimeZone() code example
Example: php datetime set timezone
$date = new \DateTime();
$date->setTimezone(new \DateTimeZone('+0800')); //GMT
echo $date->format('Y-m-d H:i:s');
// 2020-11-20 15:23:49
$date = new \DateTime();
$date->setTimezone(new \DateTimeZone('+0800')); //GMT
echo $date->format('Y-m-d H:i:s');
// 2020-11-20 15:23:49