Flight Achmad Yani International Airport departs from Semarang Achmad Yani International Airport at 08:05 and arrives at Singapore Changi Airport at 11:10.
The flighttime is about 2h 05m. The distance travelled ("as the bird flies"): 760 Km. So the average speed is roughly 365 Km.
There is an 1 hour time difference between Semarang and Singapore
