I don't see why reinventing the wheel. ;-)
The datetime
package supports several languages and, if one is not supported, the package author will surely be glad to add it. Perhaps also an interface for printing the year in Roman numerals would be useful in the package.
\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage[italian,english]{babel}
\usepackage{datetime}
\makeatletter
\newcommand\Romanyear{\@Roman{\year}}
\makeatother
\begin{document}
\monthname, \Romanyear
\selectlanguage{italian}
\monthname, \Romanyear
\end{document}

\MONTH
and\YEAR
that does that?\renew
\year
and\month
;-)