B6 618 then DL 1655 at Boston
New York JFK → Boston → San Francisco
Timetable, Boston time
16:59B6 618 from New York JFK at the gate
16:50DL 1655 to San Francisco leaves the gate
23 h 51 apart on the timetable, overnight
DL 1655 leaves 23 h 51 after B6 618 arrives on the timetable: more than half a day, so not a connection we count.