Flight Narita International Airport departs from Tokyo Narita International Airport at 14:00 and arrives at Hong Kong Hong Kong International Airport at 17:50.
The flighttime is about 4h 50m. The distance travelled ("as the bird flies"): 3064 Km. So the average speed is roughly 634 Km.
There is an 1 hour time difference between Tokyo and Hong Kong
The best day to arrive at Tokyo is Saturday and it would be best to avoid Friday, as prices are on average 433.15% higher than on Saturday. (Average prices, based on 14128135 datapoints.)
We have a lot more statistics for flights HX 605 and between Tokyo and Hong Kong.