public function GetCommentCountSince($DiscussionID, $DateAllViewed) {
		// Only for members
		if(!Gdn::Session()->IsValid()) return;
		
		// Validate DiscussionID
		$DiscussionID = (int) $DiscussionID;
		if (!$DiscussionID)
			throw new Exception('A valid DiscussionID is required in GetCommentCountSince.');
		
		// Get new comment count
		return Gdn::Database()->SQL()
			->From('Comment c')
			->Where('DiscussionID', $DiscussionID)
			->Where('DateInserted >', Gdn_Format::ToDateTime($DateAllViewed))
			->GetCount();
	}