DL 670 then B6 503 at JFK
San Francisco → New York → San Juan
Timetable, New York time
06:47DL 670 from San Francisco at the gate
19:30B6 503 to San Juan leaves the gate
12 h 43 apart on the timetable
B6 503 leaves 12 h 43 after DL 670 arrives on the timetable: more than half a day, so not a connection we count.