F9 4409 then DL 818 at Atlanta
Washington → Atlanta → Dallas-Fort Worth
Timetable, Atlanta time
23:13F9 4409 from Washington at the gate
22:49DL 818 to Dallas-Fort Worth leaves the gate
23 h 36 apart on the timetable, overnight
DL 818 leaves 23 h 36 after F9 4409 arrives on the timetable: more than half a day, so not a connection we count.