DL 939 then AA 4493 at JFK
Los Angeles → New York → Boston
Timetable, New York time
20:59DL 939 from Los Angeles at the gate
20:00AA 4493 to Boston leaves the gate
23 h 01 apart on the timetable, overnight
AA 4493 leaves 23 h 01 after DL 939 arrives on the timetable: more than half a day, so not a connection we count.