- print_r: documentation ( source)
<?php
$dt1 = new DateTimeImmutable('2020-07-18 18:30:00', new DateTimeZone('Europe/Berlin'));
$dt2 = new DateTimeImmutable('2020-07-18 16:30:00', new DateTimeZone('UTC'));
print_r($dt1->diff($dt2));
echo "\nstill here?\n";