AA 1844 then UA 1840 at Miami
San Francisco → Miami → Chicago O'Hare
Timetable, Miami time
08:17AA 1844 from San Francisco at the gate
16:50UA 1840 to Chicago O'Hare leaves the gate
8 h 33 apart on the timetable
The last days
AA 1844 and UA 1840 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.