WN 4755 then DL 5667 at Boston
Nashville → Boston → Washington National
Timetable, Boston time
11:15WN 4755 from Nashville at the gate
18:00DL 5667 to Washington National leaves the gate
6 h 45 apart on the timetable
The last days
WN 4755 and DL 5667 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.