Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_name_21 (airing_date VARCHAR, genre VARCHAR, number_of_episodes VARCHAR)
### Question:
What is the airing date for a modern drama with more than 21 episodes?
### Answer:
SELECT airing_date FROM table_name_21 WHERE genre = "modern drama" AND number_of_episodes > 21