On what date did Gunnar Nilsson make the fastest lap?
CREATE TABLE table_name_38 (date VARCHAR, fastest_lap VARCHAR)
SELECT date FROM table_name_38 WHERE fastest_lap = "gunnar nilsson"
### Context: CREATE TABLE table_name_38 (date VARCHAR, fastest_lap VARCHAR) ### Question: On what date did Gunnar Nilsson make the fastest lap? ### Answer: SELECT date FROM table_name_38 WHERE fastest_lap = "gunnar nilsson"