Today is the last Sunday of Advent. The last candle to be lit is referred to as the Peace Candle.
Traditional Advent calendars were made of paper and imported from Germany. The boxes for the days of the season were shaped like windows and one was opened on every day of Advent. The numbers for each day were placed arbitrarily so that part of the fun was finding the appropriate day. The windows opened either onto religious scenes or images of toys, musical instruments or sweets.