BA 1499 then DL 59 at Heathrow
Glasgow → London → Boston
Timetable, London time
09:50BA 1499 from Glasgow at the gate
09:40DL 59 to Boston leaves the gate
23 h 50 apart on the timetable, overnight
DL 59 leaves 23 h 50 after BA 1499 arrives on the timetable: more than half a day, so not a connection we count.