Flight Narita International Airport departs from Tokyo Narita International Airport at 18:05 and arrives at Taipei Taoyuan International Airport at 21:15.
The flighttime is about 4h 10m. The distance travelled ("as the bird flies"): 2260 Km. So the average speed is roughly 542 Km.
There is an 1 hour time difference between Tokyo and Taipei
The best day to arrive at Tokyo is Thursday and it would be best to avoid Monday, as prices are on average 1600.23% higher than on Thursday. (Average prices, based on 2137973 datapoints.)
We have a lot more statistics for flights JL 809 and between Tokyo and Taipei.