Flight Sydney Airport departs from Sydney Sydney Airport at 22:00 and arrives at Melbourne Melbourne Airport at 23:30.
The flighttime is about 1h 30m. The distance travelled ("as the bird flies"): 787 Km. So the average speed is roughly 525 Km.
The best day to arrive at Sydney is Tuesday and it would be best to avoid Friday, as prices are on average 218.92% higher than on Tuesday. (Average prices, based on 36681597 datapoints.)
We have a lot more statistics for flights JQ 539 and between Sydney and Melbourne.