AS 580 then DL 438 at Seattle
San Francisco → Seattle → Boston
Timetable, Seattle time
12:56AS 580 from San Francisco at the gate
11:45DL 438 to Boston leaves the gate
22 h 49 apart on the timetable, overnight
DL 438 leaves 22 h 49 after AS 580 arrives on the timetable: more than half a day, so not a connection we count.