Flight Incheon International Airport departs from Seoul Incheon International Airport at 08:50 and arrives at Singapore Changi Airport at 14:25.
The flighttime is about 6h 35m. The distance travelled ("as the bird flies"): 2923 Km. So the average speed is roughly 444 Km.
There is an 1 hour time difference between Seoul and Singapore
The best day to arrive at Seoul is Saturday and it would be best to avoid Monday, as prices are on average 117.74% higher than on Saturday. (Average prices, based on 690200 datapoints.)
We have a lot more statistics for flights SQ 607 and between Seoul and Singapore.