Macao sets its own “World Forest Day” on 21 March every year. This is not an international festive day and it should be properly named as “Arbor Day”. Arbor Day originated in ancient Palestine. Due to the differences in climate around the world, the tree planting activities in various places also differ from each other, so as the dates of their Arbor Day. If you line up all the Arbor Days around the world, you may find that there would be an Arbor Day somewhere in the world every month. Some places even hold tree planting month to enhance forestation.