Hello juliamb
Except for Supersaver tickets which are tied to a specific connection and itinerary, in Switzerland you do not buy a ticket for a train yet for a route.
If your ticket reads Point-to-point, it is good to travel the indicated route in the given direction(s) while you can choose the departure time according to your needs.
Day passes allow unlimited travel within their range of validity and time.
Kind regards,
Roland