When did the venue of round 3 happen?
CREATE TABLE "pre_season_cup_group_stage" (
  "date" text,
  "home_team" text,
  "score" text,
  "away_team" text,
  "venue" text,
  "crowd" text,
  "report" text
);
SELECT "date" FROM "pre_season_cup_group_stage" WHERE "venue"='round 3';