I want to buy a Swiss travel pass online tonight. We hope to arrive in Zurich the morning of September 14. When and how does the pass become active? On the first train? Obviously I don't want to activate it yet. Any reason not to buy it on Happy Rails website which is a little cheaper? When we get to Zurich, do we just look for the appropriate train, board it, and show our passes to the staff member on the train?
I thought I knew what I was doing but am suddenly a little stressed!