DL 2709 then UA 3902 at Houston
Atlanta → Houston → Washington
Timetable, Houston time
13:23DL 2709 from Atlanta at the gate
12:30UA 3902 to Washington leaves the gate
23 h 07 apart on the timetable, overnight
UA 3902 leaves 23 h 07 after DL 2709 arrives on the timetable: more than half a day, so not a connection we count.