Flight Soekarno–Hatta International Airport departs from Jakarta Soekarno–Hatta International Airport at 21:05 and arrives at Medan Kualanamu International Airport at 23:25.
The flighttime is about 2h 20m. The distance travelled ("as the bird flies"): 895 Km. So the average speed is roughly 384 Km.
The best day to arrive at Jakarta is Tuesday and it would be best to avoid Saturday, as prices are on average 30.51% higher than on Tuesday. (Average prices, based on 752819809 datapoints.)
We have a lot more statistics for flights IU 3884 and between Jakarta and Medan.