Flight Guangzhou Baiyun International Airport departs from Guangzhou Guangzhou Baiyun International Airport at 23:45 and arrives at Bangkok Don Mueang International Airport at 01:40.
The flighttime is about 2h 55m. The distance travelled ("as the bird flies"): 1440 Km. So the average speed is roughly 494 Km.
There is an 1 hour time difference between Guangzhou and Bangkok