\documentclass[basque, twocolumn]{article}
\usepackage{babel}
\usepackage[useregional]{datetime2}
\usepackage{pgffor}

\makeatletter
\newcommand{\changeyear}[1]{%
\def\@dtm@currentyear{#1}
}
\newcommand{\changemonth}[1]{%
\def\@dtm@currentmonth{#1}
}
\newcommand{\changeday}[1]{%
\def\@dtm@currentday{#1}
}
\makeatother

\begin{document}
\DTMlangsetup[basque]{inessive=true}
\foreach \myyear in {2000,...,2005}{
  \changeyear{\myyear}
  \foreach \mymonth in {1,...,12}{
    \changemonth{\mymonth}
    \foreach \myday in {1,...,31}{
      \changeday{\myday}
      \today\par
    }
    \newpage
  }
}


% \changemonth{2}
% \changeday{13}
% This PDF was created on \today.

% \changeyear{2001}
% This PDF was created on \today.
\end{document}


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%%% mode: latex
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