DL 1091 then UA 1971 at San Francisco
Salt Lake City → San Francisco → Chicago O'Hare
Timetable, San Francisco time
23:59DL 1091 from Salt Lake City at the gatealso VS 4542
22:45UA 1971 to Chicago O'Hare leaves the gatealso AC 4200
22 h 46 apart on the timetable, overnight
UA 1971 leaves 22 h 46 after DL 1091 arrives on the timetable: more than half a day, so not a connection we count.