CREATE TABLE table_19587 ("Number of episode" FLOAT, "Number of season" FLOAT, "Title  ( original ) " TEXT, "Title  ( English ) " TEXT, "Original air date" TEXT)

What was the original air date for episode number 6?
SELECT "Original air date" FROM table_19587 WHERE "Number of episode" = '6'
SELECT "Original air date" FROM "table_19587" WHERE "Number of episode" = '6'