An Advent Calendar is a special calendar used to count down the days until Christmas. Traditionally, it starts on December 1 and ends on December 24, the night before Christmas Day. Each day, a door or window is opened to reveal a small gift, treat, or a festive image, helping to build excitement for the holiday. Originally, Advent calendars were created in the 19th century in Germany and were often handmade. Today, they come in various forms, including chocolate-filled versions, toy calendars, and even digital formats. The calendar serves as a fun way to celebrate the Advent season leading up to Christmas.