Flight Bandaranaike International Airport departs from Colombo Bandaranaike International Airport at 17:35 and arrives at Guangzhou Guangzhou Baiyun International Airport at 02:05.
The flighttime is about 6h 00m. The distance travelled ("as the bird flies"): 3684 Km. So the average speed is roughly 614 Km.
There is an 2.5 hour time difference between Colombo and Guangzhou
THB