On what date did the opponent in the Toshiaki Sakai final play on a grass surface?
CREATE TABLE table_name_99 (
    date VARCHAR,
    opponent_in_the_final VARCHAR,
    surface VARCHAR
)
SELECT date FROM table_name_99 WHERE opponent_in_the_final = "toshiaki sakai" AND surface = "grass"
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: On what date did the opponent in the Toshiaki Sakai final play on a grass surface? ### Input: CREATE TABLE table_name_99 (
    date VARCHAR,
    opponent_in_the_final VARCHAR,
    surface VARCHAR
) ### Response: SELECT date FROM table_name_99 WHERE opponent_in_the_final = "toshiaki sakai" AND surface = "grass"