The International Day of Non-Violence is observed on 2 October, the birthday of Mahatma Gandhi. It is referred to in India as Gandhi Jayanti. Gandhi was the pre-eminent political and ideological leader of India during the Indian independence movement. His life was dedicated to resistance to tyranny through mass civil disobedience and non-violence.

In 2004, Iranian Nobel laureate Shirin Ebadi took a proposal for an International Day of Non-Violence to the World Social Forum in Mumbai. The idea gradually attracted the interest among India’s leaders. In 2007 President of the Indian National Congress, Sonia Gandhi, and Desmond Tutu called upon the United Nations to adopt the idea.

On 15 June 2007 the United National voted to establish 2 October as the International Day of Non-Violence and asks all members of the UN system to commemorate 2 October in by disseminating the message of non-violence, through education and public awareness.

Summarized from Wikipedia.