MX 811 then UA 8172 at San Francisco
Cincinnati → San Francisco → Boston
Timetable, San Francisco time
12:01MX 811 from Cincinnati at the gate
12:45UA 8172 to Boston leaves the gate
44 min apart on the timetable
The last days
MX 811 and UA 8172 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.