Flight Kansai International Airport departs from Osaka Kansai International Airport at 23:25 and arrives at Singapore Changi Airport at 04:40.
The flighttime is about 6h 15m. The distance travelled ("as the bird flies"): 3803 Km. So the average speed is roughly 608 Km.
There is an 1 hour time difference between Osaka and Singapore
The best day to arrive at Osaka is Saturday and it would be best to avoid Friday, as prices are on average 544.43% higher than on Saturday. (Average prices, based on 141265 datapoints.)
We have a lot more statistics for flights SQ 623 and between Osaka and Singapore.