when was the premiere of the episode where the amount of North American spectators was 1.76 millions?
CREATE TABLE table_21979779_1 (original_air_date VARCHAR, us_viewers__million_ VARCHAR)
SELECT original_air_date FROM table_21979779_1 WHERE us_viewers__million_ = "1.76"
<s>[INST] Write mssql query to answer the following question given the database schema. Schema: CREATE TABLE table_21979779_1 (original_air_date VARCHAR, us_viewers__million_ VARCHAR) Question: when was the premiere of the episode where the amount of North American spectators was 1.76 millions? [/INST] SELECT original_air_date FROM table_21979779_1 WHERE us_viewers__million_ = "1.76" </s>