what are all the date for gt3 winner oliver bryant matt harris
CREATE TABLE "calendar" (
  "round" real,
  "circuit" text,
  "date" text,
  "length" text,
  "pole_position" text,
  "gt3_winner" text,
  "gtc_winner" text
);
SELECT "date" FROM "calendar" WHERE "gt3_winner"='Oliver Bryant Matt Harris';