NH 8 then UA 3900 at San Francisco
Tokyo Narita → San Francisco → Hong Kong
Timetable, San Francisco time
09:20NH 8 from Tokyo Narita at the gatealso TG 6094, UA 7950
07:00UA 3900 to Hong Kong leaves the gate
21 h 40 apart on the timetable, overnight
UA 3900 leaves 21 h 40 after NH 8 arrives on the timetable: more than half a day, so not a connection we count.