AS 767 then DL 4623 at Seattle
Tucson → Seattle → Nashville
Timetable, Seattle time
08:37AS 767 from Tucson at the gate
17:30DL 4623 to Nashville leaves the gate
8 h 53 apart on the timetable
Seattle’s board gives a departure time for only about 58% of its flights, so many days show no gate time.
The last days
AS 767 and DL 4623 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.