AA 1333 then UA 3876 at O'Hare
Philadelphia → Chicago → Miami
Timetable, Chicago time
23:30AA 1333 from Philadelphia at the gate
21:00UA 3876 to Miami leaves the gate
21 h 30 apart on the timetable, overnight
UA 3876 leaves 21 h 30 after AA 1333 arrives on the timetable: more than half a day, so not a connection we count.