DL 499 then UA 4743 at Denver
Boston → Denver → Salt Lake City
Timetable, Denver time
10:26DL 499 from Boston at the gate
08:00UA 4743 to Salt Lake City leaves the gate
21 h 34 apart on the timetable, overnight
UA 4743 leaves 21 h 34 after DL 499 arrives on the timetable: more than half a day, so not a connection we count.