UA 3901 then IB 4975 at San Francisco
Hong Kong → San Francisco → New York JFK
Timetable, San Francisco time
16:34UA 3901 from Hong Kong at the gate
12:08IB 4975 to New York JFK leaves the gate
19 h 34 apart on the timetable, overnight
IB 4975 leaves 19 h 34 after UA 3901 arrives on the timetable: more than half a day, so not a connection we count.