I will need two tickets: Zurich airport to Fribourg and then Fribourg to Basel. I can do it on-line or I can wait and buy them on the day at the station.

My question: is there any advantage to buying on-line other than the obvious convenience? Are the fares less expensive if I buy on line at the 30-days out max point?

Thanks for this clarification.

Go to www.sbb.ch and under "Travelcards & tickets" you'll find "Supersaver tickets". You can book tickets for certain trains with some discount in advance. Please note the restrictions. E. g.:
- Supersaver tickets may be purchased no more than 14 days before the desired date of travel.
- It is not possible to upgrade class, change routes or change trains using a Supersaver ticket.
- Supersaver tickets can neither be refunded nor exchanged.

If you want a flexible ticket you can easily buy on the day at the station.

Thanks for the info; just what I was looking for.

I've purchased online from them (notify your credit card you are making an overseas internet purchase first). I was getting Supersaver tickets, but it did require selecting a station to pick up the ticket. This was two years ago so perhaps they have a print your own ticket option now.

>>>Supersaver tickets may be purchased no more than 14 days before the desired date of travel.<<<<

I think perhaps that translated poorly as you must buy at least 13 days in advance.

These Supersaver tickets are exclusively available as online tickets and print@home, no pickup at a station.

"you must buy at least 13 days in advance" - NOT true. They are in fact only available for one of the following 14 days, not longer in advance.