UA 3752 then AS 277 at San Francisco
Denver → San Francisco → New York JFK
Timetable, San Francisco time
13:00UA 3752 from Denver at the gate
13:43AS 277 to New York JFK leaves the gate
43 min apart on the timetable
The last days
UA 3752 and AS 277 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.