Zurich Station H.B. To Zurich Airport transit time?

I wasn't aware that there are trains running from Zurich to India, so I'm assuming you have a flight to catch..? If you want to arrive in Zurich (main station or HB, that is) by 8:00 am, you'd have to take the train leaving Interlaken Ost station at 6:01 am. The connecting train in Bern will be crammed though, since this is a very busy commuter line during weekdays. There are roughly 9 trains from Zurich main station to Zurich airport every hour, and it will take you between 9 and 13 minutes to get there. Should you want to travel from Interlaken directly to Zurich airport, without the need to be in central Zurich at 8:00 am, you could take any train leaving Interlaken Ost between 6:00 and (roughly) 8:30 am. Either way, there's no need to spend the night before in Zurich, and picking the train as your means of transport is the best way of getting around Switzerland. You can check the timetables of trains yourself: http://fahrplan.sbb.ch/bin/query.exe/en?

go to the source page which is swiss rail. enter interlaken as FROM and zurich Flughafen as TO. put in the date and approximate departure time. you will get a list of trips. some of the airport trips require a transfer in zurich you will see alternative routes. good luck