UA 3913 then UA 2196 at Houston
Denver → Houston → Raleigh-Durham
Timetable, Houston time
21:22UA 3913 from Denver at the gate
12:05UA 2196 to Raleigh-Durham leaves the gate
14 h 43 apart on the timetable, overnight
UA 2196 leaves 14 h 43 after UA 3913 arrives on the timetable: more than half a day, so not a connection we count.