i am going to purchase an 8 day swiss pass. Can I buy one with an open starting date? All of the sites that I have seen , require a firm starting date.
I suppose you mean a Swiss Travel Pass, as a Swiss Pass is an annual card for Swiss citizens. A Swiss Travel Pass indeed requires a fixed start date nowadays. You can order a print at home pass from the websites listed here until 3-4 business days before you intend to use it. If you are still not sure about the start date by then you can best visit a staffed train station in Switzerland, during opening hours. Be sure to take along all travelers and all passports if you buy at a station.
Enjoy your trip!