Hey all! I'm figuring out which Interrail pass to buy and I'm doubting between a Global Pass for 5 days or for 7 days. Is it possible to now choose for 5 days, and to 'upgrade' that later (either before using the first travel day or even after using the first travel day) to 7 days? Pr is that a decision I have to made before buying the ticket?
Thanks a lot in advance!
