What is the release date for the set "Ola de frío"?
release date is the date of card set being released; set "Ola de frío" refers to translation = 'Ola de frío'
SELECT T1.releaseDate FROM sets AS T1 INNER JOIN set_translations AS T2 ON T2.setCode = T1.code WHERE T2.translation = 'Ola de frío'