UA 4500 then AS 737 at Dulles
Detroit → Washington → Seattle
Timetable, Washington time
21:17UA 4500 from Detroit at the gate
17:17AS 737 to Seattle leaves the gate
20 h apart on the timetable, overnight
AS 737 leaves 20 h after UA 4500 arrives on the timetable: more than half a day, so not a connection we count.