Flight Changi Airport departs from Singapore Changi Airport at 17:50 and arrives at Guangzhou Guangzhou Baiyun International Airport at 21:50.
The flighttime is about 4h 00m. The distance travelled ("as the bird flies"): 1282 Km. So the average speed is roughly 320 Km.
The best day to arrive at Singapore is Thursday and it would be best to avoid Saturday, as prices are on average 1104.62% higher than on Thursday. (Average prices, based on 309053 datapoints.)
We have a lot more statistics for flights CZ 3040 and between Singapore and Guangzhou.