SQ 1539 then CX 7944 at San Francisco
Boston → San Francisco → Seattle
Timetable, San Francisco time
09:40SQ 1539 from Boston at the gate
06:08CX 7944 to Seattle leaves the gatealso QR 8805
20 h 28 apart on the timetable, overnight
CX 7944 leaves 20 h 28 after SQ 1539 arrives on the timetable: more than half a day, so not a connection we count.