World Book and Copyright Day (also known as International Day of the Book or World Book Days) is a yearly event on 23 April, organized by UNESCO to promote reading, publishing and copyright. The Day was first celebrated in 1995 and in 2012 the UK World Book day was celebrated on March 1, 2012.
World Book Day was celebrated for the first time on April 23. The connection between 23 April and books was first made in 1923 by booksellers in Spain as a way to honour the author Miguel de Cervantes who died on that day.
In 1995, UNESCO decided that the World Book and Copyright Day would be celebrated on this date because of the Catalonian festival and because the date is also the anniversary of the birth and death of William Shakespeare, the death of Miguel de Cervantes, Inca Garcilaso de la Vega and Josep Pla, and the birth of Maurice Druon, Vladimir Nabokov, Manuel Mejía Vallejo and Halldór Laxness.
Although 23 April is often stated as the anniversary of the deaths of both William Shakespeare and Miguel de Cervantes, this is not strictly correct. Cervantes died on 23 April according the Gregorian calendar; however, at this time England still used the Julian calendar. Whilst Shakespeare died on 23 April by the Julian calendar in use in his own country at the time, he actually died ten days after Cervantes because of the discrepancy between the two date systems. The apparent correspondence of the two dates was a fortunate coincidence for UNESCO.