UA 428 then DL 2709 at Houston
Mexico City → Houston → Atlanta
Timetable, Houston time
10:09UA 428 from Mexico City at the gate
08:05DL 2709 to Atlanta leaves the gate
21 h 56 apart on the timetable, overnight
DL 2709 leaves 21 h 56 after UA 428 arrives on the timetable: more than half a day, so not a connection we count.