UA 3851 then B6 816 at San Francisco
Rio De Janeiro → San Francisco → New York JFK
Timetable, San Francisco time
17:41UA 3851 from Rio De Janeiro at the gate
16:25B6 816 to New York JFK leaves the gate
22 h 44 apart on the timetable, overnight
B6 816 leaves 22 h 44 after UA 3851 arrives on the timetable: more than half a day, so not a connection we count.