Flight Incheon International Airport departs from Seoul Incheon International Airport at 09:55 and arrives at Macau Macau International Airport at 12:55.
The flighttime is about 4h 00m. The distance travelled ("as the bird flies"): 1654 Km. So the average speed is roughly 414 Km.
There is an 1 hour time difference between Seoul and Macau