Flight Hong Kong International Airport departs from Hong Kong Hong Kong International Airport at 14:10 and arrives at Singapore Changi Airport at 18:20.
The flighttime is about 4h 10m. The distance travelled ("as the bird flies"): 1322 Km. So the average speed is roughly 317 Km.
The best day to arrive at Hong Kong is Monday and it would be best to avoid Saturday, as prices are on average 57.75% higher than on Monday. (Average prices, based on 2013908 datapoints.)
We have a lot more statistics for flights OM 5733 and between Hong Kong and Singapore.