DL 5731 then DL 1655 at Boston
Pittsburgh → Boston → San Francisco
Timetable, Boston time
18:44DL 5731 from Pittsburgh at the gate
16:50DL 1655 to San Francisco leaves the gate
22 h 06 apart on the timetable, overnight
DL 1655 leaves 22 h 06 after DL 5731 arrives on the timetable: more than half a day, so not a connection we count.