Automatically closing threads

[hurrican]

I Currently am working with this PHP Script to close threads older than a year, but I can't seem to get it to work, on my command line, I can type
php closethreads.php and it goes on w/o error, but the threads don't lock.. I constructed this with a little bit of other codes i've found on here.. Any help is greatly appreciated!

PHP Code:

$DB_site->query("UPDATE thread
                 SET open = 0
                 WHERE dateline < ".(TIMENOW - (60 * 60 * 24 * 364))."
                  AND forumid IN (3,4,5)
");
?>