JU 8510 then UA 1971 at San Francisco
New York JFK → San Francisco → Chicago O'Hare
Timetable, San Francisco time
23:54JU 8510 from New York JFK at the gate
22:45UA 1971 to Chicago O'Hare leaves the gatealso AC 4200
22 h 51 apart on the timetable, overnight
UA 1971 leaves 22 h 51 after JU 8510 arrives on the timetable: more than half a day, so not a connection we count.