DL 9976 then DL 514 at Boston
Miami → Boston → Phoenix
Timetable, Boston time
02:50DL 9976 from Miami at the gate
08:35DL 514 to Phoenix leaves the gate
5 h 45 apart on the timetable
The last days
DL 9976 and DL 514 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.