Cadbury Dairy Milk Chocolate Advent Calender in December, Christmas, with one window open

An Advent calendar is a special calendar used to count or celebrate the days in anticipation of Christmas. Since the date of the first Sunday of Advent varies, falling between November 27 and December 3 inclusive, the Advent calendar usually begins on December 1, although many include the previous few days that are part of the season. The Advent calendar was first used by German Lutherans in the 19th and 20th centuries but is now ubiquitous among adherents of many Christian denominations. Many Advent calendars take the form of a large rectangular card with "windows", of which there are usually 24: one for each day of December leading up to Christmas Eve. Often, these windows have a Bible verse and prayer printed on them, which Christian families incorporate as part of their daily Advent devotions. Consecutive doors are opened every day leading up to Christmas. The calendar windows open to reveal an image, poem, a portion of a story (such as the story of the Nativity of Jesus) or a small gift, such as a toy or a chocolate item. Advent calendars range in theme, from sports to technology, often carrying Scripture verses