How to center text vertically in this table?
\begin{center}
\begin{tabularx}{\linewidth}{ | c | X | X | }
\hline
\textbf{Date} & \textbf{Name} & \textbf{Sign} \\
\hline
31.03.2013 & & \\
\hline
\end{tabularx}
\end{center}
Changing package is not a solution for me. How to do it in tabularx?