Need help with a hook

Detective work complete.

My objective was to do a query_posts using meta_key and meta_value_num based on the most recent comment. So I’m storing a timestamp in the postmeta. Here is the code I can up with and it’s working great.

function recent_comment_timestamp() {
	global $comment_post_ID;
	$meta_key = 'recent_comment_timestamp';
	$meta_value = time();
	update_post_meta($comment_post_ID, $meta_key, $meta_value);
}
add_action( 'wp_insert_comment', 'recent_comment_timestamp' );