DL 751 then UA 4743 at Denver
New York LaGuardia → Denver → Salt Lake City
Timetable, Denver time
10:18DL 751 from New York LaGuardia at the gate
08:00UA 4743 to Salt Lake City leaves the gate
21 h 42 apart on the timetable, overnight
UA 4743 leaves 21 h 42 after DL 751 arrives on the timetable: more than half a day, so not a connection we count.