UA 4581 then K4 532 at O'Hare
Knoxville → Chicago → Seoul
Timetable, Chicago time
11:39UA 4581 from Knoxville at the gate
06:30K4 532 to Seoul leaves the gate
18 h 51 apart on the timetable, overnight
K4 532 leaves 18 h 51 after UA 4581 arrives on the timetable: more than half a day, so not a connection we count.