I just purchased 2 tickets for my parents going from Interlaken OST to Paris Lyon.
When I was purchasing the tickets and entered the date of birth, the form kept automatically changing the date to one day earlier. So every time I entered 26, it became 25. To account for this I added one extra day to my parents date of birth and it appeared to be correct when I made payment and purchased the tickets.
However when I received the confirmation email and tickets, the date of birth was incorrect for both of my parents on the tickets. So their date of birth is one extra day for both of them (27 instead of 26 and 30 instead of 29).
Has anyone had a similar experience? What is the best way to fix this?