BA 391 then AA 107 at Heathrow
Brussels → London → New York JFK
Timetable, London time
16:20BA 391 from Brussels at the gate
15:35AA 107 to New York JFK leaves the gate
23 h 15 apart on the timetable, overnight
AA 107 leaves 23 h 15 after BA 391 arrives on the timetable: more than half a day, so not a connection we count.