Formatting datetime2 in LaTex to 4th September, 2016 without the current day?

Since you asked for a datetime2 solution:

\documentclass{article}

\usepackage[UKenglish]{babel}
\usepackage[useregional]{datetime2}

\DTMlangsetup[en-GB]{ord=raise,monthyearsep={,\space}}

\DTMsavedate{sample}{2017-01-31}

\begin{document}
\DTMusedate{sample}

\today

\end{document}

Produces

Requires datetime2 (base code) and datetime2-english (for en-GB style).