We will be staying in Zurich for a couple of nights in August and want to do a day trip up to Jungfraujoch weather permitting. Since we have a car we were thinking of driving to Interlaken and getting the train there. Seems more efficient to do it that way but we are planning from thousands of miles away. So a couple of questions? First does anyone have a better suggestion and 2nd is it ok to wait and buy train tickets the day of?