AA 3664 then UA 3902 at O'Hare
Buffalo → Chicago → Detroit
Timetable, Chicago time
12:29AA 3664 from Buffalo at the gate
12:02UA 3902 to Detroit leaves the gate
23 h 33 apart on the timetable, overnight
UA 3902 leaves 23 h 33 after AA 3664 arrives on the timetable: more than half a day, so not a connection we count.