Flight Achmad Yani International Airport departs from Semarang Achmad Yani International Airport at 20:05 and arrives at Jakarta Soekarno–Hatta International Airport at 21:15.
The flighttime is about 1h 10m. The distance travelled ("as the bird flies"): 415 Km. So the average speed is roughly 356 Km.
The best month to arrive at Semarang is January and the most expensive month to fly is May. (Average prices, based on 850 datapoints.)
We have a lot more statistics for flights SJ 225 and between Semarang and Jakarta.