CREATE TABLE table_3309 ("Circuit" CLOB, "Location" CLOB, "Date" CLOB, "Series" CLOB, "Winning driver" CLOB, "Winning team" CLOB)

When was the F4 7 series?
SELECT "Date" FROM table_3309 WHERE "Series" = 'F4 7'
SELECT "Date" FROM "table_3309" WHERE "Series" = 'F4 7'