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_3247 ( "Round" real, "Circuit" text, "Date" text, "Pole Position" text, "Fastest Lap" text, "Winning Driver" text, "Winning Team" text )

### Question ###
On what date(s) was the winning team Prema Powerteam?

### Accurate SQL ###

SELECT "Date" FROM table_3247 WHERE "Winning Team" = 'Prema Powerteam'