AA 2158 then DL 9960 at San Francisco
Chicago O'Hare → San Francisco → Seattle
Timetable, San Francisco time
00:30AA 2158 from Chicago O'Hare at the gatealso AY 4088, RJ 7305
11:15DL 9960 to Seattle leaves the gate
10 h 45 apart on the timetable
The last days
AA 2158 and DL 9960 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.