- date_default_timezone_set: documentation ( source)
<?php
date_default_timezone_set('UTC'); // fill in the blank
$timezones = array(
'Sydney' => 'Australia/Sydney',
'Melbourne' => 'Australia/Melbourne'
);
foreach ($timezones as $name => $timezone) {
$localTime = new DateTime('now', new DateTimeZone($timezone));
echo "$name: ", $localtime->format('h:ia');
}