I've concluded the 30 day Half Fare Card is the smartest choice for our 5 day stay in Switzerland. If I order the this card online (print it at home in advance on my trip), when does the 30 days starting running? Is it the date that it is sent via email, the date that I print it or the date it is first used when I arrive in Switzerland?
In the process online Before you buy it there is a step that will prompt you to pick the start date or the first date you will be in Switzerland.
Or you can buy it at the first train station you encounter in Switzerland -- I did it in Lausanne after a Paris-Lausanne SNCF ride, then bought tickets Lausanne to Mürren using the half-price discount. Took maybe ten minutes.
I would not buy it in advance, but at the first station. No chance to lose it or leave it at home!
You have to stop at the first station you encounter in Switzerland (airport or border station) in order to buy your ½ price tickets, so it is no more delay to buy your ½ price pass at the same time.
But, if you want to buy on the internet, when you buy it you are asked what start date you want.
If you have the internet version, you have to show ID (as well as your ½ price ticket and ½ price card). This is to stop you printing it out twice and two people using it. Though you could still do that if you have a friend called Susane Lindahl ☺.