Flight Soekarno–Hatta International Airport departs from Jakarta Soekarno–Hatta International Airport at 18:15 and arrives at Yogyakarta Adisutjipto International Airport at 19:40.
The flighttime is about 1h 25m. The distance travelled ("as the bird flies"): 424 Km. So the average speed is roughly 299 Km.
The best month to arrive at Jakarta is November and the most expensive month to fly is December. (Average prices, based on 295 datapoints.)
We have a lot more statistics for flights NH 5505 and between Jakarta and Yogyakarta.