AA 1992 then UA 1963 at Charlotte
St Louis → Charlotte → Denver
Timetable, Charlotte time
13:29AA 1992 from St Louis at the gate
08:36UA 1963 to Denver leaves the gate
19 h 07 apart on the timetable, overnight
UA 1963 leaves 19 h 07 after AA 1992 arrives on the timetable: more than half a day, so not a connection we count.