AA 9909 then WN 1843 at Denver
Los Angeles → Denver → St Louis
Timetable, Denver time
16:45AA 9909 from Los Angeles at the gate
16:20WN 1843 to St Louis leaves the gate
23 h 35 apart on the timetable, overnight
WN 1843 leaves 23 h 35 after AA 9909 arrives on the timetable: more than half a day, so not a connection we count.