KE 23 then QF 3748 at San Francisco
Seoul → San Francisco → San Diego
Timetable, San Francisco time
09:35KE 23 from Seoul at the gatealso DL 7860
08:20QF 3748 to San Diego leaves the gate
22 h 45 apart on the timetable, overnight
QF 3748 leaves 22 h 45 after KE 23 arrives on the timetable: more than half a day, so not a connection we count.