DL 3818 then DL 438 at Seattle
Portland (Oregon) → Seattle → Boston
Timetable, Seattle time
12:45DL 3818 from Portland (Oregon) at the gate
11:45DL 438 to Boston leaves the gate
23 h apart on the timetable, overnight
DL 438 leaves 23 h after DL 3818 arrives on the timetable: more than half a day, so not a connection we count.