Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_26464364_1 (us_air_date VARCHAR, _number VARCHAR)

### Question ###
On which date did episode # 18 air in the U.S.?

### Accurate SQL ###

SELECT us_air_date FROM table_26464364_1 WHERE _number = 18