AC 750 then B6 733 at Boston
Montréal → Boston → San Francisco
Timetable, Boston time
14:43AC 750 from Montréal at the gate
13:30B6 733 to San Francisco leaves the gate
22 h 47 apart on the timetable, overnight
B6 733 leaves 22 h 47 after AC 750 arrives on the timetable: more than half a day, so not a connection we count.