B6 8662 then B6 811 at Boston
Kansas City → Boston → Chicago O'Hare
Timetable, Boston time
14:52B6 8662 from Kansas City at the gate
17:05B6 811 to Chicago O'Hare leaves the gate
2 h 13 apart on the timetable
Boston’s board gives an arrival time for only about 59% of its flights, so many days show no gate time.
The last days
B6 8662 and B6 811 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.