CREATE TABLE table_218 ("Race Name" TEXT, "Circuit" TEXT, "Date" TEXT, "Winning driver" TEXT, "Constructor" TEXT, "Report" TEXT)

What is the date on which a race was run at Halle-Saale-Schleife circuit?
SELECT "Date" FROM table_218 WHERE "Circuit" = 'Halle-Saale-Schleife'
SELECT "Date" FROM "table_218" WHERE "Circuit" = 'Halle-Saale-Schleife'