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_15070195_1 ( date_completed VARCHAR, nickname VARCHAR )

### Question ###
when the nickname halley is used, what are the date completed

### Accurate SQL ###

SELECT date_completed FROM table_15070195_1 WHERE nickname = "Halley"