21 SeptemberIn 1981 the United Nations General Assembly passed resolution 36/67 declaring an International Day of Peace. In 2001, the United Nations General Assembly adopted a new resolution 55/282 declaring 21 September of each year as the International Day of Peace.The resolution: "Declares that the International Day of Peace shall henceforth be observed as a day of global ceasefire and non-violence, an invitation to all nations and people to honour a cessation of hostilities for the duration of the Day...“Invites all Member States, organizations of the United Nations system, and non-governmental organizations and individuals to commemorate, in an appropriate manner, the International Day of Peace, including through education and public awareness, and to cooperate with the United Nations in the establishment of the global ceasefire.”Secretary-General Kofi Annan has asked all United Nations departments and agencies to expand their observance, extending a special invitation to civil society and highlighting the Minute of Silence at 12 noon.The World Peace Prayer Society encourages participation by all individuals, organizations and schools. For complete information about the International Day of Peace, please visit:http://www.internationaldayofpeace.org
Source - http://www.worldpeace.org/peaceday.html