UA 3943 then UA 462 at Houston
Washington → Houston → Boston
Timetable, Houston time
13:47UA 3943 from Washington at the gate
16:38UA 462 to Boston leaves the gate
2 h 51 apart on the timetable
The last days
UA 3943 and UA 462 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.