UA 303 then AA 1976 at O'Hare
Kansas City → Chicago → Puerto Vallarta
Timetable, Chicago time
09:23UA 303 from Kansas City at the gate
08:43AA 1976 to Puerto Vallarta leaves the gate
23 h 20 apart on the timetable, overnight
AA 1976 leaves 23 h 20 after UA 303 arrives on the timetable: more than half a day, so not a connection we count.