Flight Haneda Airport departs from Tokyo Haneda Airport at 23:55 and arrives at Hong Kong Hong Kong International Airport at 04:15.
The flighttime is about 5h 20m. The distance travelled ("as the bird flies"): 2992 Km. So the average speed is roughly 561 Km.
There is an 1 hour time difference between Tokyo and Hong Kong
The best day to arrive at Tokyo is Sunday and it would be best to avoid Friday, as prices are on average 125.35% higher than on Sunday. (Average prices, based on 1202989 datapoints.)
We have a lot more statistics for flights UO 623 and between Tokyo and Hong Kong.
