UA 787 then K4 578 at O'Hare
Houston → Chicago → Seoul
Timetable, Chicago time
16:29UA 787 from Houston at the gate
07:40K4 578 to Seoul leaves the gate
15 h 11 apart on the timetable, overnight
K4 578 leaves 15 h 11 after UA 787 arrives on the timetable: more than half a day, so not a connection we count.