UA 3907 then UA 6157 at Houston
San Francisco → Houston → Atlanta
Timetable, Houston time
13:20UA 3907 from San Francisco at the gate
20:00UA 6157 to Atlanta leaves the gate
6 h 40 apart on the timetable
The last days
UA 3907 and UA 6157 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.