Flight Zürich Airport departs from Zurich Zürich Airport at 11:50 and arrives at Amsterdam Amsterdam Airport Schiphol at 13:30.
The flighttime is about 1h 40m. The distance travelled ("as the bird flies"): 681 Km. So the average speed is roughly 409 Km.
The best month to arrive at Zurich is August and the most expensive month to fly is March. (Average prices, based on 261 datapoints.)
We have a lot more statistics for flights KL 1920 and between Zurich and Amsterdam.