CREATE TABLE table_31521 ("Rnd" FLOAT, "Circuit" CLOB, "Location" CLOB, "Date" CLOB, "Pole position" CLOB, "Fastest lap" CLOB, "Winning driver" CLOB, "Winning team" CLOB, "Supporting" CLOB)

Who had the fastest lap on september 4?
SELECT "Fastest lap" FROM table_31521 WHERE "Date" = 'September 4'
SELECT "Fastest lap" FROM "table_31521" WHERE "Date" = 'September 4'