KE 852 then KE 23 at Incheon
Beijing Capital → Seoul → San Francisco
Timetable, Seoul time
21:55KE 852 from Beijing Capital at the gate
16:00KE 23 to San Francisco leaves the gate
18 h 05 apart on the timetable, overnight
KE 23 leaves 18 h 05 after KE 852 arrives on the timetable: more than half a day, so not a connection we count.