BA 138 then BA 930 at Heathrow
Mumbai → London → Düsseldorf
Timetable, London time
07:05BA 138 from Mumbai at the gate
06:40BA 930 to Düsseldorf leaves the gate
23 h 35 apart on the timetable, overnight
BA 930 leaves 23 h 35 after BA 138 arrives on the timetable: more than half a day, so not a connection we count.