DL 473 then DL 5679 at Boston
Seattle → Boston → Pittsburgh
Timetable, Boston time
07:35DL 473 from Seattle at the gate
20:20DL 5679 to Pittsburgh leaves the gate
12 h 45 apart on the timetable
DL 5679 leaves 12 h 45 after DL 473 arrives on the timetable: more than half a day, so not a connection we count.