Its similar to date function but formats GMT.

Example

<?php
echo date(“M d Y H:i:s”, mktime(0, 0, 0, 1, 1, 2007)).”<br />”;
echo gmdate(“M d Y H:i:s”, mktime(0, 0, 0, 1, 1, 2007));
?>

Output

Jan 01 2007 00:00:00
Dec 31 2006 18:30:00