Flight International Airport departs from Doha International Airport at 20:35 and arrives at Ho Chi Minh City Tan Son Nhat International Airport at 07:55.
The flighttime is about 7h 20m. The distance travelled ("as the bird flies"): 6081 Km. So the average speed is roughly 829 Km.
There is an 4 hour time difference between Doha and Ho Chi Minh City