DL 5731 then B6 1187 at Boston
Pittsburgh → Boston → Los Angeles
Timetable, Boston time
16:36DL 5731 from Pittsburgh at the gate
15:45B6 1187 to Los Angeles leaves the gate
23 h 09 apart on the timetable, overnight
B6 1187 leaves 23 h 09 after DL 5731 arrives on the timetable: more than half a day, so not a connection we count.