Poinsettia Day is held on December 12. Euporbia pulcherrima is discovered in 1828 by Joel Roberts Poinsett. This event in the second decade of the month december is annual.
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);
Cat Herders Day on December 15 (This is a day for everyone who has to face the frustration of trying to manage the unmanageable)