CREATE TABLE table_31354 ("No. in series" FLOAT, "Title" TEXT, "Directed by" TEXT, "Written by" TEXT, "Original air date" TEXT, "U.S. viewers  ( million ) " TEXT)

What is every original air date with U.S. viewers of 0.23 million?
SELECT "Original air date" FROM table_31354 WHERE "U.S. viewers (million)" = '0.23'
SELECT "Original air date" FROM "table_31354" WHERE "U.S. viewers (million)" = '0.23'