CREATE TABLE table_28701 ("No. in series" FLOAT, "No. in season" FLOAT, "Title" TEXT, "Directed by" TEXT, "Written by" TEXT, "Original air date" TEXT, "Production code" FLOAT, "U.S. viewers  ( millions ) " TEXT)

How many air dates had 3.2 million viewers?
SELECT COUNT("Original air date") FROM table_28701 WHERE "U.S. viewers (millions)" = '3.2'
SELECT COUNT("Original air date") FROM "table_28701" WHERE "U.S. viewers (millions)" = '3.2'