Flight Changi Airport departs from Singapore Changi Airport at 20:15 and arrives at Melbourne Melbourne Airport at 05:35.
The flighttime is about 7h 20m. The distance travelled ("as the bird flies"): 4956 Km. So the average speed is roughly 676 Km.
There is an 2 hour time difference between Singapore and Melbourne
The best day to arrive at Singapore is Saturday and it would be best to avoid Thursday, as prices are on average 527.85% higher than on Saturday. (Average prices, based on 365313 datapoints.)
We have a lot more statistics for flights QF 36 and between Singapore and Melbourne.