DL 706 then DL 850 at Atlanta
Denver → Atlanta → Washington National
Timetable, Atlanta time
18:01DL 706 from Denver at the gate
15:35DL 850 to Washington National leaves the gate
21 h 34 apart on the timetable, overnight
DL 850 leaves 21 h 34 after DL 706 arrives on the timetable: more than half a day, so not a connection we count.