AA 6451 then DL 3876 at Denver
Los Angeles → Denver → Austin
Timetable, Denver time
11:21AA 6451 from Los Angeles at the gate
09:42DL 3876 to Austin leaves the gate
22 h 21 apart on the timetable, overnight
DL 3876 leaves 22 h 21 after AA 6451 arrives on the timetable: more than half a day, so not a connection we count.