UA 648 then TP 4392 at San Francisco
Newark → San Francisco → Boston
Timetable, San Francisco time
09:30UA 648 from Newark at the gatealso VA 8516, NZ 9121
22:10TP 4392 to Boston leaves the gate
12 h 40 apart on the timetable
TP 4392 leaves 12 h 40 after UA 648 arrives on the timetable: more than half a day, so not a connection we count.