CZ 435 then AA 1503 at O'Hare
Anchorage → Chicago → Cancún
Timetable, Chicago time
15:58CZ 435 from Anchorage at the gate
08:25AA 1503 to Cancún leaves the gate
16 h 27 apart on the timetable, overnight
AA 1503 leaves 16 h 27 after CZ 435 arrives on the timetable: more than half a day, so not a connection we count.