CREATE TABLE table_21727 ("Series #" FLOAT, "Episode #" FLOAT, "Title" TEXT, "Directed by" TEXT, "Written by" TEXT, "U.S. viewers  ( million ) " TEXT, "Original airdate" TEXT, "Production Code" TEXT)

What is the original air date of episode 8? Answer: Dec. 21, 2006
SELECT COUNT("Original airdate") FROM table_21727 WHERE "Episode #" = '8'
SELECT COUNT("Original airdate") FROM "table_21727" WHERE "Episode #" = '8'