Flight Narita International Airport departs from Tokyo Narita International Airport at 18:25 and arrives at Bangkok Suvarnabhumi Airport at 23:35.
The flighttime is about 7h 10m. The distance travelled ("as the bird flies"): 4511 Km. So the average speed is roughly 629 Km.
There is an 2 hour time difference between Tokyo and Bangkok
The best day to arrive at Tokyo is Sunday and it would be best to avoid Monday, as prices are on average 755.9% higher than on Sunday. (Average prices, based on 158261 datapoints.)
We have a lot more statistics for flights JL 707 and between Tokyo and Bangkok.
