UA 1853 then AA 6439 at LAX
Cleveland → Los Angeles → San Francisco
Timetable, Los Angeles time
20:27UA 1853 from Cleveland at the gate
16:26AA 6439 to San Francisco leaves the gate
19 h 59 apart on the timetable, overnight
AA 6439 leaves 19 h 59 after UA 1853 arrives on the timetable: more than half a day, so not a connection we count.