Flight Taipei Songshan Airport departs from Taipei Taipei Songshan Airport at 16:50 and arrives at Tokyo Haneda Airport at 20:40.
The flighttime is about 3h 50m. The distance travelled ("as the bird flies"): 2157 Km. So the average speed is roughly 563 Km.
The best day to arrive at Taipei is Saturday and it would be best to avoid Tuesday, as prices are on average 162.17% higher than on Saturday. (Average prices, based on 1804918 datapoints.)
We have a lot more statistics for flights NH 854 and between Taipei and Tokyo.
