DL 155 then DL 9964 at Boston
Dublin → Boston → Atlanta
Timetable, Boston time
14:09DL 155 from Dublin at the gate
15:00DL 9964 to Atlanta leaves the gate
51 min apart on the timetable
The last days
DL 155 and DL 9964 weren’t both flown 15 min to 12 h apart in the last 21 days.
Statistics from past flights, not live flight information. Always check times and your connection with your airline, and don’t base travel or booking decisions on these numbers.