BA 1497 then B6 1621 at Heathrow
Glasgow → London → Boston
Timetable, London time
09:35BA 1497 from Glasgow at the gate
09:20B6 1621 to Boston leaves the gate
23 h 45 apart on the timetable, overnight
B6 1621 leaves 23 h 45 after BA 1497 arrives on the timetable: more than half a day, so not a connection we count.