Flight Taoyuan International Airport departs from Taipei Taoyuan International Airport at 21:05 and arrives at Hong Kong Hong Kong International Airport at 22:50.
The flighttime is about 1h 45m. The distance travelled ("as the bird flies"): 826 Km. So the average speed is roughly 472 Km.
The best day to arrive at Taipei is Saturday and it would be best to avoid Monday, as prices are on average 183.1% higher than on Saturday. (Average prices, based on 3432990 datapoints.)
We have a lot more statistics for flights CI 921 and between Taipei and Hong Kong.