DL 939 then BA 180 at JFK
Los Angeles → New York → London Heathrow
Timetable, New York time
20:59DL 939 from Los Angeles at the gate
17:50BA 180 to London Heathrow leaves the gate
20 h 51 apart on the timetable, overnight
BA 180 leaves 20 h 51 after DL 939 arrives on the timetable: more than half a day, so not a connection we count.