Flight Suvarnabhumi Airport departs from Bangkok Suvarnabhumi Airport at 17:35 and arrives at Ho Chi Minh City Tan Son Nhat International Airport at 19:05.
The flighttime is about 1h 30m. The distance travelled ("as the bird flies"): 660 Km. So the average speed is roughly 440 Km.
The best day to arrive at Bangkok is Sunday and it would be best to avoid Saturday, as prices are on average 193.77% higher than on Sunday. (Average prices, based on 6477892 datapoints.)
We have a lot more statistics for flights TG 556 and between Bangkok and Ho Chi Minh City.