DL 1223 then AM 979 at Atlanta
Cincinnati → Atlanta → Monterrey
Timetable, Atlanta time
16:33DL 1223 from Cincinnati at the gate
12:30AM 979 to Monterrey leaves the gate
19 h 57 apart on the timetable, overnight
AM 979 leaves 19 h 57 after DL 1223 arrives on the timetable: more than half a day, so not a connection we count.