Flight International Airport departs from San Francisco International Airport at 09:40 and arrives at Singapore Changi Airport at 19:05.
The flighttime is about 18h 25m. The distance travelled ("as the bird flies"): 15083 Km. So the average speed is roughly 819 Km.
There is an 15 hour time difference between San Francisco and Singapore
The best day to arrive at San Francisco is Thursday and it would be best to avoid Sunday, as prices are on average 258.7% higher than on Thursday. (Average prices, based on 93835 datapoints.)
We have a lot more statistics for flights SQ 31 and between San Francisco and Singapore.
