B6 2120 then B6 8415 at Boston
San Diego → Boston → Providence
Timetable, Boston time
06:20B6 2120 from San Diego at the gate
06:00B6 8415 to Providence leaves the gate
23 h 40 apart on the timetable, overnight
B6 8415 leaves 23 h 40 after B6 2120 arrives on the timetable: more than half a day, so not a connection we count.