Flight Narita International Airport departs from Tokyo Narita International Airport at 15:30 and arrives at Hong Kong Hong Kong International Airport at 19:55.
The flighttime is about 5h 25m. The distance travelled ("as the bird flies"): 3064 Km. So the average speed is roughly 566 Km.
There is an 1 hour time difference between Tokyo and Hong Kong
The best day to arrive at Tokyo is Tuesday and it would be best to avoid Friday, as prices are on average 60% higher than on Tuesday. (Average prices, based on 15809979 datapoints.)
We have a lot more statistics for flights HX 609 and between Tokyo and Hong Kong.