DL 706 then DL 726 at Atlanta
Denver → Atlanta → Boston
Timetable, Atlanta time
18:01DL 706 from Denver at the gate
13:50DL 726 to Boston leaves the gate
19 h 49 apart on the timetable, overnight
DL 726 leaves 19 h 49 after DL 706 arrives on the timetable: more than half a day, so not a connection we count.