Flight Haneda Airport departs from Tokyo Haneda Airport at 01:35 and arrives at Hong Kong Hong Kong International Airport at 05:15.
The flighttime is about 4h 40m. The distance travelled ("as the bird flies"): 2992 Km. So the average speed is roughly 641 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 Sunday, as prices are on average 59.83% higher than on Tuesday. (Average prices, based on 1460214 datapoints.)
We have a lot more statistics for flights NH 813 and between Tokyo and Hong Kong.