UA 2685 then DL 2709 at Houston
Merida → Houston → Atlanta
Timetable, Houston time
10:13UA 2685 from Merida at the gate
08:05DL 2709 to Atlanta leaves the gate
21 h 52 apart on the timetable, overnight
DL 2709 leaves 21 h 52 after UA 2685 arrives on the timetable: more than half a day, so not a connection we count.