F9 4409 then DL 865 at Atlanta
Washington → Atlanta → Boston
Timetable, Atlanta time
23:13F9 4409 from Washington at the gate
22:40DL 865 to Boston leaves the gate
23 h 27 apart on the timetable, overnight
DL 865 leaves 23 h 27 after F9 4409 arrives on the timetable: more than half a day, so not a connection we count.