UA 6104 then AA 2124 at O'Hare
YIP → Chicago → Los Angeles
Timetable, Chicago time
20:00UA 6104 from YIP at the gate
08:42AA 2124 to Los Angeles leaves the gate
12 h 42 apart on the timetable, overnight
AA 2124 leaves 12 h 42 after UA 6104 arrives on the timetable: more than half a day, so not a connection we count.