Flight Taoyuan International Airport departs from Taipei Taoyuan International Airport at 15:55 and arrives at Singapore Changi Airport at 20:30.
The flighttime is about 4h 35m. The distance travelled ("as the bird flies"): 2134 Km. So the average speed is roughly 466 Km.
The best day to arrive at Taipei is Tuesday and it would be best to avoid Friday, as prices are on average 67.7% higher than on Tuesday. (Average prices, based on 489027 datapoints.)
We have a lot more statistics for flights TR 899 and between Taipei and Singapore.