The best month to fly between Amsterdam and Frankfurt is August and the most expensive month to fly is June. (Average prices, based on 434 datapoints.)
The best day to arrive at Amsterdam is Tuesday and it would be best to avoid Sunday, as prices are on average 142.14% higher than on Tuesday. (Average prices, based on 443 datapoints.)
The best time to fly is at around 19. (Average prices, based on 691 datapoints.)