Good morning
A date change is not possible. If the Swiss Travel Pass is not yet valid, I recommend purchasing it again for the correct period and requesting a refund for the incorrect pass through our online form.
If the pass is already valid, it is generally not possible to refund it. If you need further assistance, call us anytime at +41 51 225 78 56 or contact us via live chat. Here on the Community, we cannot directly assist with tickets or passes.
I wish you a nice day,
Chiara_S