LA 6139 then WS 8476 at San Francisco
Boston → San Francisco → Detroit
Timetable, San Francisco time
23:58LA 6139 from Boston at the gate
23:20WS 8476 to Detroit leaves the gate
23 h 22 apart on the timetable, overnight
WS 8476 leaves 23 h 22 after LA 6139 arrives on the timetable: more than half a day, so not a connection we count.