AS 3121 then WN 2104 at Denver
San Diego → Denver → San Francisco
Timetable, Denver time
23:59AS 3121 from San Diego at the gate
08:40WN 2104 to San Francisco leaves the gate
8 h 41 apart on the timetable, overnight
The last days
AS 3121 and WN 2104 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.