user: Question: When was Pedro Rodríguez the winning driver?
Columns: ['Race', 'Circuit', 'Date', 'Pole position', 'Fastest lap', 'Winning driver', 'Constructor', 'Tyre', 'Report']
Types: ['text', 'text', 'text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['South African Grand Prix', 'Kyalami', '2 January', 'Jack Brabham', 'Denny Hulme', 'Pedro Rodríguez', 'Cooper - Maserati', 'F', 'Report']
SQL:

assistant: SELECT "Date" FROM "Table" WHERE "Winning driver" = 'Pedro Rodríguez';