Apr 14, 2012 - 5:06 PM
Regarding your questions:
1. Each of the travelers should have a Half Fare Card to be eligible to buy half fare tickets. For an overview of this card see this page
. There you'll find a PDF overview of the network on which the Half Fare Card is valid.
2. Indeed, as rahulagrin wrote, the 2 for 1 Swiss Saver Pass can only be purchased if you travel in the months of April and May.
However, which Pass will be more economical depends on the total costs of non-discounted traveling in relation to the discounts a certain Pass will give you. If you are planning to travel over longer distances it might even be better to get Swiss Saver Passes
. There's no easy way to tell. If you have an itinerary you can do the necessary calculations using the Swiss Timetable
. The FAQ on calculations
may be of help. Note that the timetable shows half fare prices by default (uncheck the half fare box if you want to see the non-discounted prices).
I hope this helps you decide.