AC 4121 then DL 6939 at San Francisco
Ontario → San Francisco → Calgary
Timetable, San Francisco time
17:50AC 4121 from Ontario at the gate
16:40DL 6939 to Calgary leaves the gate
22 h 50 apart on the timetable, overnight
DL 6939 leaves 22 h 50 after AC 4121 arrives on the timetable: more than half a day, so not a connection we count.