UA 3902 then UA 604 at Houston
Toronto → Houston → Philadelphia
Timetable, Houston time
08:27UA 3902 from Toronto at the gate
07:20UA 604 to Philadelphia leaves the gate
22 h 53 apart on the timetable, overnight
UA 604 leaves 22 h 53 after UA 3902 arrives on the timetable: more than half a day, so not a connection we count.