In 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.”
You can see a video about Peace.
You can pray.