PHP: Convert dates between timezones, independent of php timezone configuration.

gistfile1.php

<?php

  $from_value = '2011-10-04 00:00:00';

  // Create a date using the original timezone.
  $from_timezone = 'America/New_York';
  $date = new DateTime($from_value, new DateTimeZone($from_timezone));

  // Move the date to another timezone.
  $to_timezone = 'UTC';
  $date->setTimezone(new DateTimeZone($to_timezone));

  // Get the destination value in the desired format.
  $to_format = 'Y-m-d\TH:i:s'; //$to_format = 'Y-m-d H:i:s';
  $to_value = $date->format($to_format);