DL 1248 then DL 1172 at Atlanta
Harrisburg → Atlanta → Allentown
Timetable, Atlanta time
16:08DL 1248 from Harrisburg at the gate
15:20DL 1172 to Allentown leaves the gate
23 h 12 apart on the timetable, overnight
DL 1172 leaves 23 h 12 after DL 1248 arrives on the timetable: more than half a day, so not a connection we count.