Flight Incheon International Airport departs from Seoul Incheon International Airport at 23:30 and arrives at Singapore Changi Airport at 05:00.
The flighttime is about 6h 30m. The distance travelled ("as the bird flies"): 2923 Km. So the average speed is roughly 450 Km.
There is an 1 hour time difference between Seoul and Singapore
The best day to arrive at Seoul is Sunday and it would be best to avoid Monday, as prices are on average 85.52% higher than on Sunday. (Average prices, based on 275813 datapoints.)
We have a lot more statistics for flights KE 647 and between Seoul and Singapore.
INR