Flight Incheon International Airport departs from Seoul Incheon International Airport at 19:30 and arrives at Hanoi Noi Bai International Airport at 22:25.
The flighttime is about 4h 55m. The distance travelled ("as the bird flies"): 2409 Km. So the average speed is roughly 490 Km.
There is an 2 hour time difference between Seoul and Hanoi
The best day to arrive at Seoul is Friday and it would be best to avoid Monday, as prices are on average 1415.17% higher than on Friday. (Average prices, based on 542194 datapoints.)
We have a lot more statistics for flights OZ 733 and between Seoul and Hanoi.