World Environment Day has been proclaimed since December 16, 1972, at the 27th session of the UN General Assembly. It is celebrated on June 5 of each year. The date of this World Day was chosen in memory of the start of the work of the Stockholm Commission, which is concerned about human environmental issues. In its decision, the General Commission calls on States and UN agencies to hold events on this day each year to reaffirm their commitment to the preservation and improvement of the environment. At the 27th session of the General Commission, a new organization was established in the UN system, the UN Environment Program. World Environment Day is celebrated every year under the auspices of UNEP.