Flight Achmad Yani International Airport departs from Semarang Achmad Yani International Airport at 12:15 and arrives at Jakarta Soekarno–Hatta International Airport at 13:25.
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 day to arrive at Semarang is Saturday and it would be best to avoid Thursday, as prices are on average 76.54% higher than on Saturday. (Average prices, based on 103144159 datapoints.)
We have a lot more statistics for flights OD 6339 and between Semarang and Jakarta.