All Saints' Day is observed worldwide on November 1 and is celebrated by most Western churches, including the Catholic Church and various Protestant denominations. This feast, also known as the Feast of All Saints, Solemnity of All Saints, All Hallows, or Hallowmas, honors all saints, both known and unknown. The holiday originated in 609 and was initially celebrated in May before being moved to November 1 in the 8th or 9th century, likely chosen to coincide with the Celtic festival of Samhain. Customs associated with the day often include visiting the graves of deceased relatives, where people clean tombs, bring flowers, and light candles. In many Lutheran congregations, the Feast of All Saints is observed on the Sunday before or after November 1, alongside Reformation Day. In Mexico and some other regions, it is also referred to as the Day of the Innocents, honoring deceased infants and children.