DL 1223 then DL 549 at Atlanta
Cincinnati → Atlanta → Las Vegas
Timetable, Atlanta time
16:33DL 1223 from Cincinnati at the gate
13:00DL 549 to Las Vegas leaves the gate
20 h 27 apart on the timetable, overnight
DL 549 leaves 20 h 27 after DL 1223 arrives on the timetable: more than half a day, so not a connection we count.