Flight Soekarno–Hatta International Airport departs from Jakarta Soekarno–Hatta International Airport at 19:00 and arrives at Singapore Changi Airport at 21:45.
The flighttime is about 1h 45m. The distance travelled ("as the bird flies"): 369 Km. So the average speed is roughly 211 Km.
There is an 1 hour time difference between Jakarta and Singapore
The best day to arrive at Jakarta is Monday and it would be best to avoid Friday, as prices are on average 374.28% higher than on Monday. (Average prices, based on 581080986 datapoints.)
We have a lot more statistics for flights QF 822 and between Jakarta and Singapore.