Source : Webster's Revised Unabridged Dictionary (1913)

   {Ember days} (R. C. & Eng. Ch.), days set apart for fasting
      and prayer in each of the four seasons of the year. The
      Council of Placentia [A. D. 1095] appointed for ember days
      the Wednesday, Friday, and Saturday after the first Sunday
      in Lent, Whitsuntide, the 14th of September, and the 13th
      of December. The weeks in which these days fall are called
      ember weeks.