Flight Suvarnabhumi Airport departs from Bangkok Suvarnabhumi Airport at 02:25 and arrives at Tokyo Narita International Airport at 10:55.
The flighttime is about 6h 30m. The distance travelled ("as the bird flies"): 4511 Km. So the average speed is roughly 694 Km.
There is an 2 hour time difference between Bangkok and Tokyo
The best day to arrive at Bangkok is Thursday and it would be best to avoid Friday, as prices are on average 81.48% higher than on Thursday. (Average prices, based on 459770 datapoints.)
We have a lot more statistics for flights XJ 602 and between Bangkok and Tokyo.