BA 66 then BA 870 at Heathrow
Philadelphia → London → Budapest
Timetable, London time
06:35BA 66 from Philadelphia at the gate
19:25BA 870 to Budapest leaves the gate
12 h 50 apart on the timetable
BA 870 leaves 12 h 50 after BA 66 arrives on the timetable: more than half a day, so not a connection we count.