UA 3920 then AC 594 at Houston
Orlando → Houston → Toronto
Timetable, Houston time
19:47UA 3920 from Orlando at the gate
15:30AC 594 to Toronto leaves the gate
19 h 43 apart on the timetable, overnight
AC 594 leaves 19 h 43 after UA 3920 arrives on the timetable: more than half a day, so not a connection we count.