LA 6139 then KL 5638 at San Francisco
Boston → San Francisco → New York JFK
Timetable, San Francisco time
23:58LA 6139 from Boston at the gate
22:25KL 5638 to New York JFK leaves the gate
22 h 27 apart on the timetable, overnight
KL 5638 leaves 22 h 27 after LA 6139 arrives on the timetable: more than half a day, so not a connection we count.