Flight Gimpo International Airport departs from Seoul Gimpo International Airport at 16:35 and arrives at Jeju City International Airport at 17:50.
The flighttime is about 1h 15m. The distance travelled ("as the bird flies"): 271 Km. So the average speed is roughly 217 Km.
The best day to arrive at Seoul is Tuesday and it would be best to avoid Wednesday, as prices are on average 1539.75% higher than on Tuesday. (Average prices, based on 438022 datapoints.)
We have a lot more statistics for flights OZ 8967 and between Seoul and Jeju City.