user: Question: What was the date for Renato Ferreira?
Columns: ['Result', 'Opponent', 'Method', 'Event', 'Date']
Types: ['text', 'text', 'text', 'text', 'real']
Sample row: ['Loss', 'Gabriel Vella', 'Points', 'ADCC Brasil trials (Over 99KG)', 2011.0]
SQL:

assistant: SELECT "Date" FROM "Table" WHERE "Opponent" = 'Renato Ferreira';