<?php// Discover what 8am in Tokyo relates to on the East Coast of the US// Set the default timezone to Tokyo time:date_default_timezone_set('Asia/Tokyo');// Now generate the timestamp for that particular timezone, on Jan 1st, 2000$stamp = mktime(8, 0, 0, 1, 1, 2000);// Now set the timezone back to US/Easterndate_default_timezone_set('US/Eastern');// Output the date in a standard format (RFC1123), this will print:// Fri, 31 Dec 1999 18:00:00 ESTecho '<p>', date(DATE_RFC1123, $stamp) ,'</p>';?>