\documentclass{article}

\usepackage[french,spanish,english]{babel}
\usepackage{datetime}

\begin{document}
English: \today

\selectlanguage{french}
French: \today

\selectlanguage{spanish}
Spanish: \today

\begin{otherlanguage}{french}
French: \today
\end{otherlanguage}

\today
\end{document}
