DL 1007 then DL 1131 at Atlanta
Washington National → Atlanta → Houston
Timetable, Atlanta time
21:41DL 1007 from Washington National at the gate
16:12DL 1131 to Houston leaves the gate
18 h 31 apart on the timetable, overnight
DL 1131 leaves 18 h 31 after DL 1007 arrives on the timetable: more than half a day, so not a connection we count.