Flight Indira Gandhi International Airport departs from Delhi Indira Gandhi International Airport at 01:40 and arrives at Bangkok Suvarnabhumi Airport at 07:40.
The flighttime is about 4h 30m. The distance travelled ("as the bird flies"): 2606 Km. So the average speed is roughly 579 Km.
There is an 1.5 hour time difference between Delhi and Bangkok