JU 8510 then UA 1665 at San Francisco
New York JFK → San Francisco → Boston
Timetable, San Francisco time
23:54JU 8510 from New York JFK at the gate
23:20UA 1665 to Boston leaves the gatealso VA 8306, NZ 9018
23 h 26 apart on the timetable, overnight
UA 1665 leaves 23 h 26 after JU 8510 arrives on the timetable: more than half a day, so not a connection we count.