Flight Narita International Airport departs from Tokyo Narita International Airport at 09:15 and arrives at Bangkok Don Mueang International Airport at 14:45.
The flighttime is about 7h 30m. The distance travelled ("as the bird flies"): 4524 Km. So the average speed is roughly 603 Km.
There is an 2 hour time difference between Tokyo and Bangkok
The best day to arrive at Tokyo is Thursday and it would be best to avoid Saturday, as prices are on average 328.3% higher than on Thursday. (Average prices, based on 122733 datapoints.)
We have a lot more statistics for flights XJ 601 and between Tokyo and Bangkok.