B6 15 then B6 1034 at San Francisco
New York JFK → San Francisco → Boston
Timetable, San Francisco time
11:08B6 15 from New York JFK at the gatealso TP 4397
06:00B6 1034 to Boston leaves the gatealso EY 8006
18 h 52 apart on the timetable, overnight
B6 1034 leaves 18 h 52 after B6 15 arrives on the timetable: more than half a day, so not a connection we count.