AS 2129 then AS 623 at Seattle
Calgary → Seattle → San Diego
Timetable, Seattle time
09:06AS 2129 from Calgary at the gate
19:46AS 623 to San Diego leaves the gate
10 h 40 apart on the timetable
Seattle’s board gives a departure time for only about 57% of its flights, so many days show no gate time.
The last days
AS 2129 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.