UA 5576 then AA 1623 at Denver
Rapid City → Denver → Charlotte
Timetable, Denver time
06:30UA 5576 from Rapid City at the gate
06:20AA 1623 to Charlotte leaves the gate
23 h 50 apart on the timetable, overnight
AA 1623 leaves 23 h 50 after UA 5576 arrives on the timetable: more than half a day, so not a connection we count.