B6 8359 then B6 393 at Boston
New York JFK → Boston → Denver
Timetable, Boston time
08:32B6 8359 from New York JFK at the gate
08:05B6 393 to Denver leaves the gate
23 h 33 apart on the timetable, overnight
B6 393 leaves 23 h 33 after B6 8359 arrives on the timetable: more than half a day, so not a connection we count.