Flight Changi Airport departs from Singapore Changi Airport at 21:35 and arrives at Bandar Seri Begawan Brunei International Airport at 23:45.
The flighttime is about 2h 10m. The distance travelled ("as the bird flies"): 1223 Km. So the average speed is roughly 564 Km.
The best day to arrive at Singapore is Wednesday and it would be best to avoid Thursday, as prices are on average 109.84% higher than on Wednesday. (Average prices, based on 2993322 datapoints.)
We have a lot more statistics for flights BI 424 and between Singapore and Bandar Seri Begawan.