Flight King Khaled International Airport departs from Riyadh King Khaled International Airport at 02:10 and arrives at Bangkok Suvarnabhumi Airport at 13:45.
The flighttime is about 7h 35m. The distance travelled ("as the bird flies"): 5991 Km. So the average speed is roughly 790 Km.
There is an 4 hour time difference between Riyadh and Bangkok