UA 3922 then AA 1503 at O'Hare
Tampa → Chicago → Cancún
Timetable, Chicago time
11:35UA 3922 from Tampa at the gate
08:25AA 1503 to Cancún leaves the gate
20 h 50 apart on the timetable, overnight
AA 1503 leaves 20 h 50 after UA 3922 arrives on the timetable: more than half a day, so not a connection we count.