Why 15th Aug Was Chosen as Independence Day? It was all Mountbatten's idea. The story goes that Mountbatten was wondering as to what date should be the most appropriate for this momentous event in history. To his most triumphant day of his existence was 15th August, when Japan surrendered to the Allied Forces, the day he delivered as the Supreme Allied Commander, South East Asia, and hence he chose 15th of Aug.
