UA 3905 then UA 371 at San Francisco
Tokyo Haneda → San Francisco → Boston
Timetable, San Francisco time
16:33UA 3905 from Tokyo Haneda at the gate
07:00UA 371 to Boston leaves the gatealso DL 400, VS 1787, SK 3586, LY 4228, VA 8566, AF 8859, NZ 9014
14 h 27 apart on the timetable, overnight
UA 371 leaves 14 h 27 after UA 3905 arrives on the timetable: more than half a day, so not a connection we count.