CK 225 then UA 2371 at O'Hare
Seattle (SEA) → Chicago → Cancún
Timetable, Chicago time
08:44CK 225 from Seattle (SEA) at the gate
08:40UA 2371 to Cancún leaves the gate
23 h 56 apart on the timetable, overnight
UA 2371 leaves 23 h 56 after CK 225 arrives on the timetable: more than half a day, so not a connection we count.