AC 447 then UA 3903 at Toronto Pearson
Ottawa → Toronto → Houston
Timetable, Toronto time
11:20AC 447 from Ottawa at the gate
11:00UA 3903 to Houston leaves the gate
23 h 40 apart on the timetable, overnight
UA 3903 leaves 23 h 40 after AC 447 arrives on the timetable: more than half a day, so not a connection we count.