AM 90 then CZ 3090 at Incheon
Monterrey → Seoul → Shenzhen
Timetable, Seoul time
14:15AM 90 from Monterrey at the gate
13:45CZ 3090 to Shenzhen leaves the gate
23 h 30 apart on the timetable, overnight
CZ 3090 leaves 23 h 30 after AM 90 arrives on the timetable: more than half a day, so not a connection we count.