SQ 1539 then AF 5879 at San Francisco
Boston → San Francisco → Atlanta
Timetable, San Francisco time
09:40SQ 1539 from Boston at the gate
08:00AF 5879 to Atlanta leaves the gate
22 h 20 apart on the timetable, overnight
AF 5879 leaves 22 h 20 after SQ 1539 arrives on the timetable: more than half a day, so not a connection we count.