AA 9909 then DL 1940 at Denver
Los Angeles → Denver → Salt Lake City
Timetable, Denver time
16:45AA 9909 from Los Angeles at the gate
16:00DL 1940 to Salt Lake City leaves the gate
23 h 15 apart on the timetable, overnight
DL 1940 leaves 23 h 15 after AA 9909 arrives on the timetable: more than half a day, so not a connection we count.