Flight Changi Airport departs from Singapore Changi Airport at 07:25 and arrives at Jakarta Soekarno–Hatta International Airport at 08:25.
The flighttime is about 2h 00m. The distance travelled ("as the bird flies"): 369 Km. So the average speed is roughly 184 Km.
There is an 1 hour time difference between Singapore and Jakarta
The best day to arrive at Singapore is Sunday and it would be best to avoid Monday, as prices are on average 1167.01% higher than on Sunday. (Average prices, based on 289290647 datapoints.)
We have a lot more statistics for flights QF 823 and between Singapore and Jakarta.