In most French regions, the winter sales will start in 2012 on January 11th and finish on February 14th. But there are exceptions to this in six departments near the French border: Meurthe-et-Moselle, Meuse, Moselle, Vosges, Landes and Pyrenees-Atlantiques.
Sales in France are government regulated, although with tough economic conditions you'll see plenty of signs saying Promotion (deal) or Soldes exceptionnels (exceptional sales).
Sales are genuine with shops selling off out-of-season stock and as all good French women know, if you're out of season then you might as well drop out. Which makes good bargains for foreign visitors who don't care a toss about the season but want good clothes at good prices.
If you miss the sales, don't worry. There are bargains to be had in France throughout the year, particularly in the discount malls and shopping centres around the country. Check out my Bargain shopping guide.
If you're near Troyes in Champagne, don't miss the Malls just outside Troyes. Find out more.