WN 209 then AA 591 at Denver
St Louis → Denver → Charlotte
Timetable, Denver time
18:50WN 209 from St Louis at the gate
16:04AA 591 to Charlotte leaves the gate
21 h 14 apart on the timetable, overnight
AA 591 leaves 21 h 14 after WN 209 arrives on the timetable: more than half a day, so not a connection we count.