Another way to do it would be to use the [time] parameter of /timer.
E.g.
//timer $+($time($calc($ctime + 3600),HH),:,00) 1 0 echo -a This will be echo'd on the next hour
//timer $+($time($calc($ctime + 3600),HH),:,00) 0 3600 echo -a This will be echo'd on every hour after the next.
