Flight Incheon International Airport departs from Seoul Incheon International Airport at 21:15 and arrives at Hong Kong Hong Kong International Airport at 00:05.
The flighttime is about 3h 50m. The distance travelled ("as the bird flies"): 1621 Km. So the average speed is roughly 423 Km.
There is an 1 hour time difference between Seoul and Hong Kong
The best month to arrive at Seoul is October and the most expensive month to fly is June. (Average prices, based on 8601 datapoints.)
The best day to arrive at Seoul is Saturday and it would be best to avoid Sunday, as prices are on average 5.5% higher than on Saturday. (Average prices, based on 17015823 datapoints.)
We have a lot more statistics for flights GA 179 and between Seoul and Hong Kong.