KL 644 then TK 1956 at Schiphol
New York JFK → Amsterdam → Istanbul
Timetable, Amsterdam time
10:30KL 644 from New York JFK at the gate
23:10TK 1956 to Istanbul leaves the gate
12 h 40 apart on the timetable
TK 1956 leaves 12 h 40 after KL 644 arrives on the timetable: more than half a day, so not a connection we count.