Flight Changi Airport departs from Singapore Changi Airport at 21:00 and arrives at Jakarta Soekarno–Hatta International Airport at 21:50.
The flighttime is about 1h 50m. The distance travelled ("as the bird flies"): 369 Km. So the average speed is roughly 201 Km.
There is an 1 hour time difference between Singapore and Jakarta
The best day to arrive at Singapore is Thursday and it would be best to avoid Wednesday, as prices are on average 54.7% higher than on Thursday. (Average prices, based on 283018717 datapoints.)
We have a lot more statistics for flights GA 8819 and between Singapore and Jakarta.