AA 9909 then DL 1648 at Denver
Los Angeles → Denver → Detroit
Timetable, Denver time
16:45AA 9909 from Los Angeles at the gate
16:15DL 1648 to Detroit leaves the gate
23 h 30 apart on the timetable, overnight
DL 1648 leaves 23 h 30 after AA 9909 arrives on the timetable: more than half a day, so not a connection we count.