AC 4121 then UA 857 at San Francisco
Ontario → San Francisco → Shanghai
Timetable, San Francisco time
17:50AC 4121 from Ontario at the gatealso UA 5483
12:55UA 857 to Shanghai leaves the gatealso CA 7210
19 h 05 apart on the timetable, overnight
UA 857 leaves 19 h 05 after AC 4121 arrives on the timetable: more than half a day, so not a connection we count.