What was the date when Chris Amon won?
CREATE TABLE table_1140090_6 (date VARCHAR, winning_driver VARCHAR)
SELECT date FROM table_1140090_6 WHERE winning_driver = "Chris Amon"
### Context: CREATE TABLE table_1140090_6 (date VARCHAR, winning_driver VARCHAR) ### Question: What was the date when Chris Amon won? ### Answer: SELECT date FROM table_1140090_6 WHERE winning_driver = "Chris Amon"