Flight Sydney Airport departs from Sydney Sydney Airport at 09:25 and arrives at Melbourne Melbourne Airport at 11:00.
The flighttime is about 1h 35m. The distance travelled ("as the bird flies"): 787 Km. So the average speed is roughly 497 Km.
The best day to arrive at Sydney is Tuesday and it would be best to avoid Saturday, as prices are on average 167.49% higher than on Tuesday. (Average prices, based on 36440650 datapoints.)
We have a lot more statistics for flights ZL 31 and between Sydney and Melbourne.