While 23 April 1616 was recorded as his date of death in some references, and the date on which his death was widely celebrated, he in fact died in Madrid the previous day, 22 April.[21] He was buried on 23 April.[22]
William Shakespeare died on 23 April 1616. To honor this, UNESCO established 23 April as the International Day of the Book.[23] However, these dates refer to different days: Spain had adopted the Gregorian calendar in 1582, but England was still using the Julian calendar. Shakespeare's death on 23 April 1616 (Julian) was equivalent to 3 May 1616 (Gregorian). This was 10 days after Cervantes was buried and 11 days after he died.