CREATE TABLE table_17621 ("Number in series" FLOAT, "Broadcast Order" CLOB, "Title" CLOB, "Villain/s" CLOB, "U.S. Air Date" CLOB, "Production Code" CLOB)

what's the total number of episodes with a US air date of january 15, 2005?
SELECT COUNT("Production Code") FROM table_17621 WHERE "U.S. Air Date" = 'January 15, 2005'
SELECT COUNT("Production Code") FROM "table_17621" WHERE "U.S. Air Date" = 'January 15, 2005'