Ok, I got it going. Thanks again for your help.
Here is the code if anyone wants to use it.
<?
//where page3.php is the current file
putenv('TZ=US/Eastern');
mktime(0,0,0,1,1,1970);
$last_modified = (-18000);
$last_modified = filemtime("page3.php");
//print it all out
print("<b>Last Modified:</b> ");
print(date("M j, Y g:i a", $last_modified));
?>