Mr. Dayal was born in Allahabad, India, on 29 January 1935. He studied at St. Stephen's College, Delhi (1951-1956) and, as a Rhodes Scholar, at the University College, Oxford (1956-58). In 1958, Mr. Dayal joined the Indian Administrative Service. He ably served the Government of UP and the Government of India in various important positions.
Between 1965-1979, Mr. Dayal worked for the Office of the United Nations High Commissioner for Refugees (UNHCR), serving in a variety of capacities in Geneva and New York. During this period, Mr. Dayal also undertook numerous missions for the Office in Africa, Asia and the Americas. In 1971, he was part of UNHCR’s “Focal Point” team in India, assisting the millions of refugees who had entered the country from what was then East Pakistan. In 1972, he worked with the UN Relief Operation in Bangladesh. In 1973, he helped to negotiate and initiate a massive humanitarian airlift in South Asia which saw the organized movement of a quarter million people between Pakistan and Bangladesh. He was the Executive Assistant to the High Commissioner, UNHCR at the height of the “boat people” crisis which followed the end of the war in South East Asia. In 1979, Mr. Dayal was appointed Director, Office of Special Political Affairs, in the Office of the Secretary General. This office was responsible for all peace-keeping operations of the United Nations. In 1982, Mr. Dayal was asked by the Secretary General, Perez de Cuellar, to serve as his Chef de Cabinet. This he did until the end of Mr. Perez de Cuellar's term in December 1991. During this period, Mr. Dayal held the rank of Under Secretary-General. As Chef de Cabinet, Mr. Dayal's functions required deep involvement in all aspects of the work of the United Nations, including most of the major political, peace-keeping and humanitarian issues being handled by the Secretary-General. With the election of Mr. Boutros Boutros-Ghali as Secretary-General, Mr. Dayal continued to serve as Chef de Cabinet until the end of February 1992. The incoming Secretary General, thereafter, requested Mr. Dayal to assist in the writing of "An Agenda for Peace" prepared in response to the declaration adopted by the Summit Meeting of the Security Council on 31st January 1992. After returning home to India in 1992, Mr. Dayal served as member of the Indian delegation to the World Conference on Human Rights held in Vienna in June 1993. In October 1993, the President of India appointed him to a 5-year term as a Member of the National Human Rights Commission of India, established by an Act of Parliament. In November 1998, he was re-appointed for a second 5-year term as a Member of that Commission. In the course of his work, Mr. Dayal also represented the Commission in successive meetings of the U.N. Commission on Human Rights, the International Coordinating Committee of National Institutions for the Promotion and Protection of Human Rights and the Asia-Pacific Forum of such institutions. He also represented the National Human Rights Commission at the World Conference against Racism held in Durban in August-September 2001. Mr Dayal was a Member of the Carnegie Commission on Preventing Deadly Conflict, which submitted its report to the Secretary-General of the United Nations early in 1998. He is a Member of The Club of The Hague, which concerns itself with refugee and migration issues. In 1992, Mr Dayal received the national award, "Padma Bhushan, “ conferred by the President of India.