AA 4735 then B6 1355 at Boston
Syracuse → Boston → Washington National
Timetable, Boston time
11:50AA 4735 from Syracuse at the gate
16:10B6 1355 to Washington National leaves the gate
4 h 20 apart on the timetable
Boston’s board gives an arrival time for only about 58% of its flights, so many days show no gate time.
The last days
AA 4735 and B6 1355 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.