VU 311 then SQ 7440 at Bangkok
Ho Chi Minh City → Bangkok → Seoul
Timetable, Bangkok time
15:25VU 311 from Ho Chi Minh City at the gate
14:47SQ 7440 to Seoul leaves the gate
23 h 22 apart on the timetable, overnight
SQ 7440 leaves 23 h 22 after VU 311 arrives on the timetable: more than half a day, so not a connection we count.