Flight Incheon International Airport departs from Seoul Incheon International Airport at 21:05 and arrives at Shanghai Pudong International Airport at 22:25.
The flighttime is about 2h 20m. The distance travelled ("as the bird flies"): 649 Km. So the average speed is roughly 278 Km.
There is an 1 hour time difference between Seoul and Shanghai
The best day to arrive at Seoul is Sunday and it would be best to avoid Monday, as prices are on average 96.51% higher than on Sunday. (Average prices, based on 4486863 datapoints.)
We have a lot more statistics for flights CZ 370 and between Seoul and Shanghai.