Flight Hong Kong International Airport departs from Hong Kong Hong Kong International Airport at 15:05 and arrives at Singapore Changi Airport at 19:15.
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 Wednesday and it would be best to avoid Saturday, as prices are on average 95.31% higher than on Wednesday. (Average prices, based on 2005631 datapoints.)
We have a lot more statistics for flights OM 5731 and between Hong Kong and Singapore.