DL 939 then AA 100 at JFK
Los Angeles → New York → London Heathrow
Timetable, New York time
20:59DL 939 from Los Angeles at the gate
18:25AA 100 to London Heathrow leaves the gate
21 h 26 apart on the timetable, overnight
AA 100 leaves 21 h 26 after DL 939 arrives on the timetable: more than half a day, so not a connection we count.