B6 8378 then AA 4425 at Boston
Las Vegas → Boston → Buffalo
Timetable, Boston time
09:19B6 8378 from Las Vegas at the gate
08:00AA 4425 to Buffalo leaves the gate
22 h 41 apart on the timetable, overnight
AA 4425 leaves 22 h 41 after B6 8378 arrives on the timetable: more than half a day, so not a connection we count.