- date_default_timezone_set: documentation ( source)
<?php
// Source: https://bugs.php.net/bug.php?id=62476
date_default_timezone_set('Europe/Berlin');
for ($d=55; $d<65; $d++)
{
$dt = DateTime::createFromFormat ('z.Y', $d.'.2012');
$dd = $dt->format ('d.m.Y');
echo "$d $dd\n";
}