Flight Suvarnabhumi Airport departs from Bangkok Suvarnabhumi Airport at 12:15 and arrives at Xiamen Gaoqi International Airport at 16:30.
The flighttime is about 3h 15m. The distance travelled ("as the bird flies"): 1965 Km. So the average speed is roughly 605 Km.
There is an 1 hour time difference between Bangkok and Xiamen