Flight Gimpo International Airport departs from Seoul Gimpo International Airport at 19:00 and arrives at Jeju City International Airport at 20:10.
The flighttime is about 1h 10m. The distance travelled ("as the bird flies"): 271 Km. So the average speed is roughly 232 Km.
The best day to arrive at Seoul is Thursday and it would be best to avoid Tuesday, as prices are on average 900.26% higher than on Thursday. (Average prices, based on 454934 datapoints.)
We have a lot more statistics for flights KE 1209 and between Seoul and Jeju City.
INR