AA 2436 then UA 4772 at O'Hare
San Francisco → Chicago → Columbia Regional
Timetable, Chicago time
15:15AA 2436 from San Francisco at the gate
12:45UA 4772 to Columbia Regional leaves the gate
21 h 30 apart on the timetable, overnight
UA 4772 leaves 21 h 30 after AA 2436 arrives on the timetable: more than half a day, so not a connection we count.