DL 1091 then DL 8939 at San Francisco
Salt Lake City → San Francisco → Phoenix
Timetable, San Francisco time
23:55DL 1091 from Salt Lake City at the gatealso VS 4542
23:00DL 8939 to Phoenix leaves the gate
23 h 05 apart on the timetable, overnight
DL 8939 leaves 23 h 05 after DL 1091 arrives on the timetable: more than half a day, so not a connection we count.