CREATE TABLE table_17969 ("Round" FLOAT, "Circuit" TEXT, "Date" TEXT, "Length" TEXT, "Pole Position" TEXT, "GT3 Winner" TEXT, "GTC Winner" TEXT)

what are all the date for gt3 winner oliver bryant matt harris
SELECT "Date" FROM table_17969 WHERE "GT3 Winner" = 'Oliver Bryant Matt Harris'
SELECT "Date" FROM "table_17969" WHERE "GT3 Winner" = 'Oliver Bryant Matt Harris'