AA 2663 then WN 1424 at Philadelphia
San Francisco → Philadelphia → St Louis
Timetable, Philadelphia time
08:24AA 2663 from San Francisco at the gate
14:45WN 1424 to St Louis leaves the gate
6 h 21 apart on the timetable
The last days
AA 2663 and WN 1424 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.