When did the season premiere that saw 8.4 million viewers first air?
CREATE TABLE table_31392 (
    "Season" text,
    "Season premiere" text,
    "Season finale" text,
    "TV season" text,
    "Ranking" text,
    "Viewers (in millions)" text
)
SELECT "Season premiere" FROM table_31392 WHERE "Viewers (in millions)" = '8.4'
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: When did the season premiere that saw 8.4 million viewers first air? ### Input: CREATE TABLE table_31392 (
    "Season" text,
    "Season premiere" text,
    "Season finale" text,
    "TV season" text,
    "Ranking" text,
    "Viewers (in millions)" text
) ### Response: SELECT "Season premiere" FROM table_31392 WHERE "Viewers (in millions)" = '8.4'