Thank you for answering the question so promptly. I truly appreciate your effort. I have purchased grand train tour of Switzerland “Top Attractions” from STC company. They are located in Switzerland Travel Centre,Brinstrasse,38 Zürich. It is a five day and four night excursion and they have provided me, Swiss half fare cards. The card begins on July 28. I will be doing this tour from July 28 to August 2 and then i will go to to Heidelberg. The Discount card starting date is July 28 My plan was to use these Swiss Half fare cards to get the discount for my train travel, I am not sure if I am eligible to use my cards now. I question if I can I use these cards before July 28? The other possibility is that I buy the tickets to heidelberg on July 28, in that case, is there a theoretical possibility that there are no seats left on the train and the entire train train is booked and I don’t get any tickets. I like to maintain structure and avoid chaos . I will be travelling with my wife and my two boys. I do not want to take any chances, please guide me. Thank you very much. Thank you again in advance.