DL 706 then DL 1491 at Atlanta
Denver → Atlanta → Austin
Timetable, Atlanta time
18:01DL 706 from Denver at the gate
16:00DL 1491 to Austin leaves the gate
21 h 59 apart on the timetable, overnight
DL 1491 leaves 21 h 59 after DL 706 arrives on the timetable: more than half a day, so not a connection we count.