AV 2183 then SQ 1550 at San Francisco
Vancouver → San Francisco → Boston
Timetable, San Francisco time
15:27AV 2183 from Vancouver at the gate
10:44SQ 1550 to Boston leaves the gate
19 h 17 apart on the timetable, overnight
SQ 1550 leaves 19 h 17 after AV 2183 arrives on the timetable: more than half a day, so not a connection we count.