what is the date when the venue is gold coast convention centre?
CREATE TABLE "round_9" (
  "date" text,
  "home_team" text,
  "score" text,
  "away_team" text,
  "venue" text,
  "crowd" real,
  "box_score" text,
  "report" text
);
SELECT "date" FROM "round_9" WHERE "venue"='gold coast convention centre';