UA 6172 then UA 3754 at Houston
Jacksonville → Houston → Waco
Timetable, Houston time
13:20UA 6172 from Jacksonville at the gate
11:30UA 3754 to Waco leaves the gate
22 h 10 apart on the timetable, overnight
UA 3754 leaves 22 h 10 after UA 6172 arrives on the timetable: more than half a day, so not a connection we count.