Flight Gimpo International Airport departs from Seoul Gimpo International Airport at 14:45 and arrives at Jeju City International Airport at 15:55.
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 Friday and it would be best to avoid Sunday, as prices are on average 291.81% higher than on Friday. (Average prices, based on 693357 datapoints.)
We have a lot more statistics for flights OZ 8965 and between Seoul and Jeju City.