Hamburg is 8 hours ahead of Calgary
Best overlap: 8:00 AM to 10:00 AM in Calgary is 4:00 PM to 6:00 PM in Hamburg.
For the smoothest call, aim inside 8:00 AM to 10:00 AM in Calgary, i.e. 4:00 PM to 6:00 PM in Hamburg. The overlap barely stretches to 2 hours, so reserve it for what really needs a live conversation and handle the rest async.