Flight International Airport departs from San Francisco International Airport at 11:15 and arrives at Singapore Changi Airport at 18:45.
The flighttime is about 16h 30m. The distance travelled ("as the bird flies"): 15083 Km. So the average speed is roughly 914 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 379.48% higher than on Thursday. (Average prices, based on 21883 datapoints.)
We have a lot more statistics for flights UA 29 and between San Francisco and Singapore.