BA 929 then BA 199 at Heathrow
Hannover → London → Mumbai
Timetable, London time
22:35BA 929 from Hannover at the gate
20:15BA 199 to Mumbai leaves the gate
21 h 40 apart on the timetable, overnight
BA 199 leaves 21 h 40 after BA 929 arrives on the timetable: more than half a day, so not a connection we count.