Flight Narita International Airport departs from Tokyo Narita International Airport at 21:00 and arrives at Hong Kong Hong Kong International Airport at 00:45.
The flighttime is about 4h 45m. The distance travelled ("as the bird flies"): 3064 Km. So the average speed is roughly 645 Km.
There is an 1 hour time difference between Tokyo and Hong Kong
The best day to arrive at Tokyo is Wednesday and it would be best to avoid Monday, as prices are on average 566.74% higher than on Wednesday. (Average prices, based on 16177486 datapoints.)
We have a lot more statistics for flights HX 631 and between Tokyo and Hong Kong.
