Flight King Khaled International Airport departs from Riyadh King Khaled International Airport at 22:10 and arrives at Seoul Incheon International Airport at 14:40.
The flighttime is about 10h 30m. The distance travelled ("as the bird flies"): 8805 Km. So the average speed is roughly 839 Km.
There is an 6 hour time difference between Riyadh and Seoul