UA 3913 then UA 3754 at Houston
Denver → Houston → Waco
Timetable, Houston time
21:22UA 3913 from Denver at the gate
11:30UA 3754 to Waco leaves the gate
14 h 08 apart on the timetable, overnight
UA 3754 leaves 14 h 08 after UA 3913 arrives on the timetable: more than half a day, so not a connection we count.