My Growing Season Nativity Advent Calendar This beautifully detailed Nativity Advent Calendar provides a religious backdrop to the excitement little ones (and big ones) have of counting down till Christmas day. Dimensions: 24" tall x 14" wide on a 16" dowel. Starting on December 1st, simply remove and place one ornament on the manger scene each day until December 24. Ornaments include Mary, Joseph, the Three Wise Men, shepherds, animals, and more.