- date_create: documentation ( source)
<?php
$tz1 = new DateTimezone("America/Los_angeles");
$tz2 = new DateTimezone("Europe/Budapest");
echo date_create("1970-11-01 03:25:45")->format("Y-m-d H:i:s");
echo PHP_EOL;
echo date_create("1970-11-01 03:25:45", $tz)->format("Y-m-d H:i:s");