LA 6139 then UA 368 at San Francisco
Boston → San Francisco → Chicago O'Hare
Timetable, San Francisco time
23:58LA 6139 from Boston at the gate
23:30UA 368 to Chicago O'Hare leaves the gatealso AC 4372, NZ 9307
23 h 32 apart on the timetable, overnight
UA 368 leaves 23 h 32 after LA 6139 arrives on the timetable: more than half a day, so not a connection we count.