CZ 3605 then CZ 339 at Guangzhou
Yanji → Guangzhou → Seoul
Timetable, Guangzhou time
18:55CZ 3605 from Yanji at the gate
17:30CZ 339 to Seoul leaves the gate
22 h 35 apart on the timetable, overnight
CZ 339 leaves 22 h 35 after CZ 3605 arrives on the timetable: more than half a day, so not a connection we count.