UA 3851 then AC 571 at San Francisco
Rio De Janeiro → San Francisco → Vancouver
Timetable, San Francisco time
17:41UA 3851 from Rio De Janeiro at the gate
16:55AC 571 to Vancouver leaves the gatealso TP 8023
23 h 14 apart on the timetable, overnight
AC 571 leaves 23 h 14 after UA 3851 arrives on the timetable: more than half a day, so not a connection we count.