Flight Don Mueang International Airport departs from Bangkok Don Mueang International Airport at 18:25 and arrives at Surat Thani Surat Thani International Airport at 19:35.
The flighttime is about 1h 10m. The distance travelled ("as the bird flies"): 187 Km. So the average speed is roughly 160 Km.
The best day to arrive at Bangkok is Monday and it would be best to avoid Saturday, as prices are on average 118.66% higher than on Monday. (Average prices, based on 723034 datapoints.)
We have a lot more statistics for flights DD 578 and between Bangkok and Surat Thani.