DL 459 then B6 1187 at Boston
Seattle → Boston → Los Angeles
Timetable, Boston time
16:00DL 459 from Seattle at the gate
15:45B6 1187 to Los Angeles leaves the gate
23 h 45 apart on the timetable, overnight
B6 1187 leaves 23 h 45 after DL 459 arrives on the timetable: more than half a day, so not a connection we count.