\documentclass{article}
\begin{document}

Default: (Left) Justified.

Date right justified:


\begin{flushright}
  
   Goiânia, \today
\end{flushright}

\begin{center}
   Why
   \begin{flushleft}
      Should anything
   \end{flushleft}
   Be unjustified?
\end{center}



olllalala

\centering{I should be centered}

oallalla
\end{document}
