Flight Changi Airport departs from Singapore Changi Airport at 10:00 and arrives at Hong Kong Hong Kong International Airport at 14:00.
The flighttime is about 4h 00m. The distance travelled ("as the bird flies"): 1322 Km. So the average speed is roughly 330 Km.
The best day to arrive at Singapore is Saturday and it would be best to avoid Wednesday, as prices are on average 255.05% higher than on Saturday. (Average prices, based on 3163840 datapoints.)
We have a lot more statistics for flights OM 5618 and between Singapore and Hong Kong.