IB 345 then AS 257 at Boston
Madrid → Boston → Seattle
Timetable, Boston time
18:00IB 345 from Madrid at the gate
16:33AS 257 to Seattle leaves the gate
22 h 33 apart on the timetable, overnight
AS 257 leaves 22 h 33 after IB 345 arrives on the timetable: more than half a day, so not a connection we count.