WN 120 then UA 1639 at Denver
Kansas City → Denver → St Louis
Timetable, Denver time
15:20WN 120 from Kansas City at the gate
13:55UA 1639 to St Louis leaves the gate
22 h 35 apart on the timetable, overnight
UA 1639 leaves 22 h 35 after WN 120 arrives on the timetable: more than half a day, so not a connection we count.