\begin{figure}[!h]
    \centering
    \begin{tikzpicture}
        % draw horizontal line
        \draw (0,0) -- (1,0);
        \draw (1,0) -- (7,0) node[pos=.5,above] {(estimation window]};
        \draw (7,0) -- (8,0);
        \draw (8,0) -- (11,0)  node[pos=.5,above] {(event window]};
        \draw [->](11,0) -- (12,0);

        % draw vertical line
        \foreach \x in {1,7,8,9.5,11}
                \draw (\x cm,3pt) -- (\x cm,-3pt);   
        % draw nodes
        \draw (1,0) node[below=3pt] {$ T_{0} $} node[above=3pt] {$ $};
        \draw (7,0) node[below=3pt] {$ T_{1} $} node[above=3pt] {$ $};
        \draw (8,0) node[below=3pt] {$ T_{2} $} node[above=3pt] {$ $};
        \draw (9.5,0) node[below=3pt] {$ 0 $} node[above=3pt] {$ $};
        \draw (11,0) node[below=3pt] {$ T_{3} $} node[above=3pt] {$ $};
        \draw (12,0) node[below=3pt] {$ \tau $} node[above=3pt] {$ $};
    \end{tikzpicture}
    \caption{Event Study Timeline}
    \label{figure03}
\end{figure}