DL 939 then DL 457 at JFK
Los Angeles → New York → Denver
Timetable, New York time
20:59DL 939 from Los Angeles at the gate
17:50DL 457 to Denver leaves the gate
20 h 51 apart on the timetable, overnight
DL 457 leaves 20 h 51 after DL 939 arrives on the timetable: more than half a day, so not a connection we count.