DL 543 then DL 9963 at Atlanta
St Louis → Atlanta → Queretaro
Timetable, Atlanta time
20:10DL 543 from St Louis at the gate
09:30DL 9963 to Queretaro leaves the gate
13 h 20 apart on the timetable, overnight
DL 9963 leaves 13 h 20 after DL 543 arrives on the timetable: more than half a day, so not a connection we count.