UA 3852 then VA 8546 at San Francisco
Seoul → San Francisco → Los Angeles
Timetable, San Francisco time
08:46UA 3852 from Seoul at the gate
06:00VA 8546 to Los Angeles leaves the gate
21 h 14 apart on the timetable, overnight
VA 8546 leaves 21 h 14 after UA 3852 arrives on the timetable: more than half a day, so not a connection we count.