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_21055055_2 ( au_air_date VARCHAR, viewers__m_ VARCHAR )

### Question ###
When did the episode seen by is 2.267 million people get aired?

### Accurate SQL ###

SELECT au_air_date FROM table_21055055_2 WHERE viewers__m_ = "2.267"