DL 939 then B6 615 at JFK
Los Angeles → New York → San Francisco
Timetable, New York time
20:59DL 939 from Los Angeles at the gate
17:55B6 615 to San Francisco leaves the gate
20 h 56 apart on the timetable, overnight
B6 615 leaves 20 h 56 after DL 939 arrives on the timetable: more than half a day, so not a connection we count.