AA 2124 then UA 2831 at LAX
Chicago O'Hare → Los Angeles → San Francisco
Timetable, Los Angeles time
11:37AA 2124 from Chicago O'Hare at the gate
11:35UA 2831 to San Francisco leaves the gate
23 h 58 apart on the timetable, overnight
UA 2831 leaves 23 h 58 after AA 2124 arrives on the timetable: more than half a day, so not a connection we count.