WITH a 1/2 fare card, saver day passes purchased 30 days in advance are "advertised" as 29SFR/2nd class and 49SFR/1st class (with increasing prices up to the day before travel). The real saving comes if you use them on weekends (when the 9 o'clock day cards are not valid).
If you're looking for a direct link:
https://www.sbb.ch/en/travelcards-an...-day-pass.html
Some great savings, even without the half fare card (Halbtax). And the T&C state that there are no time restrictions. The most expensive option is for the next day: CHF 59.00 (full fare CHF 109.00) but with no time restrictions still more attractive than the 9 o'clock day pass.