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_24399615_4 (airdate VARCHAR, cable_rank VARCHAR)

### Question ###
What date did the episode air that had a ranking of 17 for cable?

### Accurate SQL ###

SELECT airdate FROM table_24399615_4 WHERE cable_rank = "17"