My younger brother and his wife will be traveling in march from Barcelona to interlaken Switzerland . They are looking forward to seeing the countryside and wish to take daytime trains to their destination. We are having trouble finding information about anything other than the night train. They are inexperienced travelers and we would like to have this part of the trip organized before they go. They must be in interlaken evening of march 20. Thanks for any help .

not taken that route by train ,but the main Spanish train site is
www.renfe.es
they should have info there.hope it helps