CREATE TABLE table_21974 ("Episode" CLOB, "Broadcast date" CLOB, "Run time" CLOB, "Viewers  ( in millions ) " CLOB, "Archive" CLOB)

What is the broadcast date when 8.3 million viewers watched?
SELECT "Broadcast date" FROM table_21974 WHERE "Viewers (in millions)" = '8.3'
SELECT "Broadcast date" FROM "table_21974" WHERE "Viewers (in millions)" = '8.3'