The United Nations’ (UN) International Day of Peace is celebrated on September 21 each year to recognize the efforts of those who have worked hard to end conflict and promote peace. The International Day of Peace is also a day of ceasefire – personal or political.
In 2002 the General Assembly officially declared September 21 as the permanent date for the International Day of Peace. The International Day of Peace or the “Peace Day” provides an opportunity for people, organizations and nations to create practical acts of peace on a shared date. It was established by a United Nations resolution in 1981 to coincide with the opening of the General Assembly. The first Peace Day was celebrated in September 1982.
More about Peace Day: http://peaceoneday.org/press/