UA 784 then UA 4743 at Denver
Mexico City → Denver → Salt Lake City
Timetable, Denver time
11:54UA 784 from Mexico City at the gate
08:00UA 4743 to Salt Lake City leaves the gate
20 h 06 apart on the timetable, overnight
UA 4743 leaves 20 h 06 after UA 784 arrives on the timetable: more than half a day, so not a connection we count.