CREATE TABLE table_29442 ("Episode" TEXT, "Date" TEXT, "Official ITV rating  ( millions ) " TEXT, "Weekly rank" FLOAT, "Share  ( % ) " TEXT, "Official ITV HD rating  ( millions ) " TEXT, "Total ITV viewers  ( millions ) " TEXT)

What date was the show's weekly ranking 12?
SELECT "Date" FROM table_29442 WHERE "Weekly rank" = '12'
SELECT "Date" FROM "table_29442" WHERE "Weekly rank" = '12'