WN 262 then UA 1639 at Denver
Las Vegas → Denver → St Louis
Timetable, Denver time
17:40WN 262 from Las Vegas at the gate
13:55UA 1639 to St Louis leaves the gate
20 h 15 apart on the timetable, overnight
UA 1639 leaves 20 h 15 after WN 262 arrives on the timetable: more than half a day, so not a connection we count.