UA 1241 then UA 3754 at Houston
Denver → Houston → Waco
Timetable, Houston time
13:31UA 1241 from Denver at the gate
11:30UA 3754 to Waco leaves the gate
21 h 59 apart on the timetable, overnight
UA 3754 leaves 21 h 59 after UA 1241 arrives on the timetable: more than half a day, so not a connection we count.