★Arbor Day (Day of Trees)
April 10 (the US, Canada, Australia...)

In many countries it has long been the tradition to hold an annual tree or forest festival. The origin of such celebrations dates back to antiquity and is in the dawn of religious feeling and awe for what trees represented. However, Arbor Day, as it is commonly known today, is of American origin and evolved from conditions peculiar to the Great Plains. It was first observed in Nebraska in 1872.

The idea, conceived by J.S. Morton, then a member of the Nebraska State Board of Agriculture, was one of forest conservation. It was a move to promote replanting, following deforestation, and to plant up treeless areas. The idea has spread widely to other lands where it is variously celebrated as the 'Festival of Trees', 'Greening Week' of Japan, 'The New Year's Days of Trees' in Israel, 'The Tree-loving Week' of Korea, 'The Reforestation Week' of Yugoslavia, 'The Students' Afforestation Day' of Iceland and 'The National Festival of Tree Planting' in India. Arbor Day in its various forms is now recognised in more than fifty countries.