AA 3978 then UA 4736 at Denver
Phoenix Sky Harbor → Denver → Hobbs
Timetable, Denver time
18:13AA 3978 from Phoenix Sky Harbor at the gate
14:10UA 4736 to Hobbs leaves the gate
19 h 57 apart on the timetable, overnight
UA 4736 leaves 19 h 57 after AA 3978 arrives on the timetable: more than half a day, so not a connection we count.