DL 58 then BA 1382 at Heathrow
Boston → London → Manchester
Timetable, London time
06:50DL 58 from Boston at the gate
19:05BA 1382 to Manchester leaves the gate
12 h 15 apart on the timetable
BA 1382 leaves 12 h 15 after DL 58 arrives on the timetable: more than half a day, so not a connection we count.