CREATE TABLE table_25768 ("No. in series" FLOAT, "Title" CLOB, "Directed by" CLOB, "Written by" CLOB, "Original air date" CLOB, "Production code" CLOB, "U.S. viewers  ( millions ) " CLOB)

When did 6.09 million people in the US see the original airing of an episode of the show?
SELECT "Original air date" FROM table_25768 WHERE "U.S. viewers (millions)" = '6.09'
SELECT "Original air date" FROM "table_25768" WHERE "U.S. viewers (millions)" = '6.09'