- var_dump: documentation ( source)
<?php
$dt = new DateTime('2022-03-19 16:00:00', new DateTimeZone('America/Mexico_City'));
var_dump($dt->format(DateTimeInterface::RFC822));
$dt->setTimezone(new DateTimeZone('UTC'));
$dt->modify('+1 year +2 month');
$dt->setTimezone(new DateTimeZone('America/Mexico_City'));
var_dump($dt->format(DateTimeInterface::RFC822));