WN 757 then UA 549 at Denver
Cleveland → Denver → Des Moines
Timetable, Denver time
18:45WN 757 from Cleveland at the gate
17:48UA 549 to Des Moines leaves the gate
23 h 03 apart on the timetable, overnight
UA 549 leaves 23 h 03 after WN 757 arrives on the timetable: more than half a day, so not a connection we count.