Spanish to English Law/Patents Law (general) Date format in Peruvian Birth Cert

I am translating a birth certifiate from Soras, Sucre Province, Ayacucho, Peru. It's certification form ends with: "Comas 15 de 02 de 1999." I know that it's meaning that the copy was certified on the 15th of February of 1999, but I am at a loss as to how to translate the word "comas." I surely would appeciate insights into this!!! Thanks in advance! -Laura