AA 1844 then DL 1399 at Miami
San Francisco → Miami → Boston
Timetable, Miami time
08:17AA 1844 from San Francisco at the gate
11:37DL 1399 to Boston leaves the gate
3 h 20 apart on the timetable
The last days
AA 1844 and DL 1399 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.