I have a one night stop-over in ZRH arriving from DUS and will continue the next morning to JFK. There was never a problem to check the luggage to ZRH and the next day recheck the luggage to JFK. But this time I have two pieces of luggage to be checked-in: can I just check in one piece to ZRH and another one directly DUS-ZRH-JFK with the second leg the next day?