Flight Soekarno–Hatta International Airport departs from Jakarta Soekarno–Hatta International Airport at 17:45 and arrives at Medan Kualanamu International Airport at 20:10.
The flighttime is about 2h 25m. The distance travelled ("as the bird flies"): 895 Km. So the average speed is roughly 370 Km.
The best day to arrive at Jakarta is Sunday and it would be best to avoid Friday, as prices are on average 52.56% higher than on Sunday. (Average prices, based on 750259922 datapoints.)
We have a lot more statistics for flights GA 1824 and between Jakarta and Medan.