Using the PHP DateTime() object

datetime.php

<?php
date_default_timezone_set('UTC');

$deadline = '2013-09-13 13:00:00'; // UTC

$timezones = array(
	'America/Los_Angeles',
	'America/New_York',
	'UTC',
	'Europe/London',
	'Europe/Berlin',
	'Europe/Minsk'
);

foreach ($timezones as $timezone) {
	$t = new DateTime;
	$t->setTimestamp(strtotime($deadline));
	$t->setTimezone(new DateTimeZone($timezone));
	var_dump($t);

}