"The traditional [advent] calendar consists of two pieces of card stock on top of each other. Twenty-four doors are cut out in the top layer, with a number ranging from one to twenty-four on each. Beginning on the first day of December, one door is opened each day [containing a chocolate and/or showing an illustration related to Christmas], counting down the days remaining until Christmas Eve, from one to twenty-four where the 24th door often holds an extra surprise like an extra large piece of chocolate."
