KE 852 then KE 1409 at Incheon
Beijing Capital → Seoul → Busan
Timetable, Seoul time
21:55KE 852 from Beijing Capital at the gate
19:35KE 1409 to Busan leaves the gate
21 h 40 apart on the timetable, overnight
KE 1409 leaves 21 h 40 after KE 852 arrives on the timetable: more than half a day, so not a connection we count.