DL 1204 then DL 825 at Atlanta
Kansas City → Atlanta → Las Vegas
Timetable, Atlanta time
08:45DL 1204 from Kansas City at the gate
21:15DL 825 to Las Vegas leaves the gate
12 h 30 apart on the timetable
DL 825 leaves 12 h 30 after DL 1204 arrives on the timetable: more than half a day, so not a connection we count.