DL 1218 then UA 4749 at Detroit
Austin → Detroit → Chicago O'Hare
Timetable, Detroit time
16:05DL 1218 from Austin at the gate
10:48UA 4749 to Chicago O'Hare leaves the gate
18 h 43 apart on the timetable, overnight
UA 4749 leaves 18 h 43 after DL 1218 arrives on the timetable: more than half a day, so not a connection we count.