Flight Changi Airport departs from Singapore Changi Airport at 13:30 and arrives at Guangzhou Guangzhou Baiyun International Airport at 17:50.
The flighttime is about 4h 20m. The distance travelled ("as the bird flies"): 1282 Km. So the average speed is roughly 296 Km.
The best day to arrive at Singapore is Monday and it would be best to avoid Wednesday, as prices are on average 220.53% higher than on Monday. (Average prices, based on 307083 datapoints.)
We have a lot more statistics for flights CZ 354 and between Singapore and Guangzhou.