WN 3299 then AS 623 at Seattle
Dallas → Seattle → San Diego
Timetable, Seattle time
10:25WN 3299 from Dallas at the gate
19:46AS 623 to San Diego leaves the gate
9 h 21 apart on the timetable
Seattle’s board gives a departure time for only about 59% of its flights, so many days show no gate time.
The last days
WN 3299 and AS 623 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.