List of the Official Annual International Days related to Forestry, Environment, Wildlife.
These are the international days currently observed by the United Nations. The United Nations designates specific days, weeks, years and decades as occasions to mark particular events or topics in order to promote, through awareness and action, the objectives of the Organization. Usually, it is one or more Member States that propose these observances and the General Assembly establishes them with a resolution. On occasion, these celebrations are declared by the specialized agencies of the United Nations, such as UNESCO, UNICEF, FAO, etc., when they concern issues that fall within the scope of their competencies. Some of them may be later adopted by the General Assembly.

March 3 – World Wildlife Day
March 21 – International Day of Forests
March 22 – World Water Day
March 23 – World Meteorological Day
April 7 – World Health Day
April 18 – International Day For Monuments and Sites
April 22 – Earth Day
May 11 – (Second Saturday of May)
World Migratory Bird Day
May 20 – World Bee Day
May 22 – International Day for Biological Diversity
June 5 – World Environment Day
June 5 – International Day for the Fight against Illegal, Unreported and Unregulated Fishing
June 8 – World Oceans Day
June 17 – World Day to Combat Desertification and Drought
September 16 – International Day for the Preservation of the Ozone Layer
September 27 – World Tourism Day
Last Thursday of September – World Maritime Day
First Monday in October – World Habitat Day
October 13 – International Day for Disaster Reduction
November 5 – World Tsunami Awareness Day
December 5 – World Soil Day
December 11 – International Mountain Day
Source: UN International Days