What date did episode 15 of the season originally air?
CREATE TABLE table_21172539_1 (original_air_date VARCHAR, no_in_season VARCHAR)
SELECT original_air_date FROM table_21172539_1 WHERE no_in_season = 15
<s>[INST] Write mssql query to answer the following question given the database schema. Schema: CREATE TABLE table_21172539_1 (original_air_date VARCHAR, no_in_season VARCHAR) Question: What date did episode 15 of the season originally air? [/INST] SELECT original_air_date FROM table_21172539_1 WHERE no_in_season = 15 </s>