KE 852 then KE 459 at Incheon
Beijing Capital → Seoul → Da Nang
Timetable, Seoul time
21:55KE 852 from Beijing Capital at the gate
18:40KE 459 to Da Nang leaves the gate
20 h 45 apart on the timetable, overnight
KE 459 leaves 20 h 45 after KE 852 arrives on the timetable: more than half a day, so not a connection we count.