DL 20 then DL 8800 at Boston
Seattle → Boston → Miami
Timetable, Boston time
02:30DL 20 from Seattle at the gate
11:10DL 8800 to Miami leaves the gate
8 h 40 apart on the timetable
The last days
DL 20 and DL 8800 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.