Choral Day is held on December 8. This event in the first decade of the month december is annual.
International Sweater Vestival on December 6 (Festival of Sweater Vests - fun unofficial Christmas fashion-related holiday featured);
World Techno Day on December 9 (Juan Atkins was born on Dec 9, 1962, and was part of the Belleville Three, so named because of their time together in Belleville, Michigan);
Poinsettia Day on December 12 (Euporbia pulcherrima is discovered in 1828 by Joel Roberts Poinsett);