Flight Soekarno–Hatta International Airport departs from Jakarta Soekarno–Hatta International Airport at 09:35 and arrives at Bangkok Suvarnabhumi Airport at 13:10.
The flighttime is about 3h 35m. The distance travelled ("as the bird flies"): 830 Km. So the average speed is roughly 232 Km.
The best day to arrive at Jakarta is Monday and it would be best to avoid Friday, as prices are on average 40.43% higher than on Monday. (Average prices, based on 41249138 datapoints.)
We have a lot more statistics for flights KE 866 and between Jakarta and Bangkok.