World Poetry Day is celebrated on 21 March, and was declared by UNESCO (the United Nations Educational, Scientific and Cultural Organization) in 1999. Its purpose is to promote the reading, writing, publishing and teaching of poetry throughout the world and, as the original UNESCO declaration says, to "give fresh recognition and impetus to national, regional and international poetry movements".
It was generally celebrated in October, but in the latter part of the 20th century the world community celebrated it on the 15th, the birthday of Virgil, the Roman epic poet and poet laureate under Augustus. The tradition to keep an October date for national or international poetry day celebrations still holds in many countries. The United Kingdom generally uses the first Thursday in October, which in 2018 falls on October 4, but elsewhere a different October, or even sometimes a November date, is celebrated.