UA 617 then UA 5539 at O'Hare
Denver → Chicago → Cleveland
Timetable, Chicago time
17:05UA 617 from Denver at the gate
10:50UA 5539 to Cleveland leaves the gate
17 h 45 apart on the timetable, overnight
UA 5539 leaves 17 h 45 after UA 617 arrives on the timetable: more than half a day, so not a connection we count.