I am a bit confused about the Swiss 15 day travel Pass. in order to use the STP each day, must I sign in the SBB website EACH DAY?
From the readings in various forum notes, I was under the impression that all one needs to do is show the STP to the various train conductors when they ask. The pass is for valid 15 days, doesn't the QR code indicate the dates of validity?
Yes, you just need to show the QR code, either on your phone or a printed out copy.
You may also be asked for your ID/passport.
It sounds like you might be talking about the Flex version of the Swiss Travel Pass.
It is a continuous 15 day pass, so now need do anything except show it to conductors. Perhaps you are confusing it with the "15 days out 30 days" Flex Pass. For that you must validate you are using it for particular days.
I thank both of you for this clarification. It was my misreading of how to use the pass. I feel much more confident in train, bus and boat planned excursions. I appreciate that each of you took an opportunity to share your knowledge with me.
Do not bother with the Flex Pass. That is not good value in my opinion, as you need to activate a day even if you only plan to use the pass to get a discount (eg. on a mountain railway or cable car). Get the continuous pass, or if you do not plan to move around enough to justify that get the Half Fare Card.