human
Considering the provided database schema and associated query, produce SQL code to retrieve the answer to the query. 
###Database Schema: Airing date, Number of episodes, HD format, Highest average point ratings, Genre, Official website
###Question: What was the airing date when the number of episodes was larger than 20 and had the genre of costume action?
gpt
SELECT Airing date FROM table WHERE Number of episodes > 20 AND Genre = costume action