Which former Prime Minister's death anniversary is celebrated on 31 October every year in India?

In the year 2019, 35th death anniversary of former Prime Minister of India Indira Gandhi is being celebrated. He first assumed the position of Minister of Information and Broadcasting during the tenure of Prime Minister Lal Bahadur Shastri. After this, on Shastri's death, she was elected the third Prime Minister of the country. In 1971, he was awarded the Bharat Ratna. He was assassinated on 31 October 1984 while he was the Prime Minister.