AS 2129 then DL 3911 at Seattle
Calgary → Seattle → Santa Ana
Timetable, Seattle time
09:06AS 2129 from Calgary at the gate
15:29DL 3911 to Santa Ana leaves the gate
6 h 23 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 DL 3911 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.