DL 9951 then DL 549 at Atlanta
Queretaro → Atlanta → Las Vegas
Timetable, Atlanta time
20:38DL 9951 from Queretaro at the gate
13:00DL 549 to Las Vegas leaves the gate
16 h 22 apart on the timetable, overnight
DL 549 leaves 16 h 22 after DL 9951 arrives on the timetable: more than half a day, so not a connection we count.