Flight Achmad Yani International Airport departs from Semarang Achmad Yani International Airport at 10:55 and arrives at Seletar Seletar Airport at 13:55.
The flighttime is about 10h 00m. The distance travelled ("as the bird flies"): 773 Km. So the average speed is roughly 77 Km.
There is an 7 hour time difference between Semarang and Seletar