AC 570 then B6 1534 at San Francisco
Vancouver → San Francisco → Boston
Timetable, San Francisco time
23:01AC 570 from Vancouver at the gatealso NZ 4508, UA 8174
22:10B6 1534 to Boston leaves the gatealso EY 8032
23 h 09 apart on the timetable, overnight
B6 1534 leaves 23 h 09 after AC 570 arrives on the timetable: more than half a day, so not a connection we count.