QR 31 then AA 1503 at O'Hare
Milan → Chicago → Cancún
Timetable, Chicago time
11:14QR 31 from Milan at the gate
08:25AA 1503 to Cancún leaves the gate
21 h 11 apart on the timetable, overnight
AA 1503 leaves 21 h 11 after QR 31 arrives on the timetable: more than half a day, so not a connection we count.