DL 499 then AF 8 at Boston
Denver → Boston → New York JFK
Timetable, Boston time
17:27DL 499 from Denver at the gate
20:15AF 8 to New York JFK leaves the gate
2 h 48 apart on the timetable
The last days
DL 499 and AF 8 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.