UA 21 then UA 3754 at Houston
Amsterdam → Houston → Waco
Timetable, Houston time
14:35UA 21 from Amsterdam at the gate
11:30UA 3754 to Waco leaves the gate
20 h 55 apart on the timetable, overnight
UA 3754 leaves 20 h 55 after UA 21 arrives on the timetable: more than half a day, so not a connection we count.