B6 778 then B6 633 at Boston
Las Vegas → Boston → San Francisco
Timetable, Boston time
06:32B6 778 from Las Vegas at the gate
06:00B6 633 to San Francisco leaves the gate
23 h 28 apart on the timetable, overnight
B6 633 leaves 23 h 28 after B6 778 arrives on the timetable: more than half a day, so not a connection we count.