CREATE TABLE table_204_562 (id NUMBER, "no." NUMBER, "date" CLOB, "location" CLOB, "surface" CLOB, "opponent in final" CLOB, "score" CLOB)

what was the only day grass was the surface used ?
SELECT "date" FROM table_204_562 WHERE "surface" = 'grass'
SELECT "date" FROM "table_204_562" WHERE "surface" = 'grass'