UA 3913 then UA 4352 at Houston
Denver → Houston → Panama City Beach
Timetable, Houston time
21:22UA 3913 from Denver at the gate
12:35UA 4352 to Panama City Beach leaves the gate
15 h 13 apart on the timetable, overnight
UA 4352 leaves 15 h 13 after UA 3913 arrives on the timetable: more than half a day, so not a connection we count.