UA 97 then UA 8222 at San Francisco
Brisbane → San Francisco → Boston
Timetable, San Francisco time
06:30UA 97 from Brisbane at the gatealso AV 2054, LX 3089, VA 8507, LH 8947
13:15UA 8222 to Boston leaves the gate
6 h 45 apart on the timetable
The last days
UA 97 and UA 8222 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.