AA 4639 then DL 688 at JFK
Boston → New York → Seattle
Timetable, New York time
07:29AA 4639 from Boston at the gate
19:30DL 688 to Seattle leaves the gate
12 h 01 apart on the timetable
DL 688 leaves 12 h 01 after AA 4639 arrives on the timetable: more than half a day, so not a connection we count.