What were the dates when 224 Assassin's Creed: Brotherhood Circus Training was shown on Tuesday?
CREATE TABLE "table1_18173916_6" (
  "episodes" text,
  "monday" text,
  "tuesday" text,
  "wednesday" text,
  "thursday" text,
  "friday" text
);
SELECT "episodes" FROM "table1_18173916_6" WHERE "tuesday"='224 Assassin''s Creed: Brotherhood Circus Training';