And these are scheduled for 2012 (with some holidays & other events):
February 21, 2012 - Mardi Gras
February 24-25, 2012 - D'Iberville, MS (IBCA)
February 23-25, 2012 - Houston Livestock Show & Rodeo World's Championship Bar-B-Que Contest
March 2-3, 2012 - Gonzales, LA (St. Jude Bayou BBQ)(IBCA)
March 9-10, 2012 - Baton Rouge, LA (KCBS)
March 9-10, 2012 - Marksville, LA (Spring Throwdown)(IBCA)
March 16-17, 2012 - Alexandria, LA (MBN)
March 23-24, 2012 - Hammond, LA (KCBS)
March 24, 2012 - New Orleans, LA (High on the Hog pork cookoff) (non-sanctioned)
March 30-31, 2012 - Slidell, LA (KCBS)
April 8, 2012 - Easter Sunday
(tentative - pending approval)April 20-21, 2012 - Leesville, LA (IBCA)
May 4-5, 2012 - Lafayette, LA (IBCA)
May 18-19, 2012 - Lake Charles, LA (IBCA)
June 1-2, 2012 - Natchitoches, LA (IBCA)
June 8-9, 2012 - Eunice, LA (IBCA)
July 13-14, 2012 - Morgan City, LA (IBCA)
September 14-15, 2012 - Port Allen, LA (IBCA)
September 21-22, 2012 - Gonzales, LA (Safety Council BBQ) (IBCA)
(tentative - pending approval)November 2-3, 2012 - Florien, LA (IBCA)
(this list is a work in progress)
The reasoning behind this is that most contests plan on holding their next contest on the same weekend as in the past; depending on circumstances, this can change.
Be sure to check the website of the contest's sanctioning body for the final word on when a contest will be held.