UA 3920 then UA 2190 at Houston
Orlando → Houston → Las Vegas
Timetable, Houston time
19:47UA 3920 from Orlando at the gate
17:00UA 2190 to Las Vegas leaves the gate
21 h 13 apart on the timetable, overnight
UA 2190 leaves 21 h 13 after UA 3920 arrives on the timetable: more than half a day, so not a connection we count.