The Last-Modified header is set in includes/bootstrap.inc. Plain Drupal uses
header("Last-Modified: ". gmdate("D, d M Y H:i:s") ." GMT");
Last-Modified: Sun, 27 Jan 2013 21:52:57 GMT
$default_headers = array( 'Last-Modified' => gmdate(DATE_RFC1123, $_SERVER['REQUEST_TIME']),
Last-Modified: Sun, 27 Jan 2013 21:52:57 +0000
'+0000' is incorrect according to RFC 2616, and is flagged as an invalid date by http://redbot.org/
What gives? Is this a Pressflow performance technique, or an error, or what? Do browsers care?
We're trying to nail down some load issues on our site, and want to be sure we are not getting more repeat requests than is appropriate.