There will be no S-Bahn service to Stadthausbrücke and Landungsbrücken this Sunday, 1 December because of engineering works on the City-Tunnel. Trains between Hauptbahnhof and Altona will run via Dammtor. There will be a replacement bus service between Baumwall and Altona. If you usually use the S-Bahn to get to church, allow plenty of extra time. The HVV website has details.