WN 209 then UA 5239 at Denver
St Louis → Denver → Midland
Timetable, Denver time
18:50WN 209 from St Louis at the gate
13:40UA 5239 to Midland leaves the gate
18 h 50 apart on the timetable, overnight
UA 5239 leaves 18 h 50 after WN 209 arrives on the timetable: more than half a day, so not a connection we count.