AA 1356 then B6 1603 at JFK
Las Vegas → New York → San Juan
Timetable, New York time
07:11AA 1356 from Las Vegas at the gate
19:30B6 1603 to San Juan leaves the gate
12 h 19 apart on the timetable
B6 1603 leaves 12 h 19 after AA 1356 arrives on the timetable: more than half a day, so not a connection we count.