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_15823956_1 ( region_1 VARCHAR, series VARCHAR )

### Question ###
What is the region 1 date for series 4

### Accurate SQL ###

SELECT region_1 FROM table_15823956_1 WHERE series = "4"