HotTopics zeitlich begrenzen

function get_hottopics($limit = 10) {
    global $wpdb, $post;
    $mostcommenteds = $wpdb->get_results("SELECT  $wpdb->posts.ID, post_title, post_name, post_date, 
COUNT($wpdb->comments.comment_post_ID) 
AS 'comment_total' FROM 
$wpdb->posts LEFT JOIN $wpdb->comments ON $wpdb->posts.ID = $wpdb->comments.comment_post_ID 
WHERE comment_approved = '1' 
AND post_date_gmt < '".gmdate("Y-m-d H:i:s")."' 
AND post_status = 'publish' 
AND post_password = '' GROUP BY $wpdb->comments.comment_post_ID 
ORDER  BY comment_total DESC LIMIT $limit");
    foreach ($mostcommenteds as $post) {
            $post_title = htmlspecialchars(stripslashes($post->post_title));
            $comment_total = (int) $post->comment_total;
            echo "<li><a href=\"".get_permalink()."\">$post_title&nbsp;<strong>($comment_total)</strong></a></li>";
    }
}