Flight Suvarnabhumi Airport departs from Bangkok Suvarnabhumi Airport at 18:40 and arrives at Kuala Lumpur Kuala Lumpur International Airport at 21:55.
The flighttime is about 2h 15m. The distance travelled ("as the bird flies"): 259 Km. So the average speed is roughly 115 Km.
There is an 1 hour time difference between Bangkok and Kuala Lumpur