\begin{table}
%\centering
\par
\caption{Journal of WHT observations.\label{jan}}
\begin{tabular}{cccc}
\hline\hline
Date & $\lambda$-range   & $\Delta\lambda$& Exp. Time\\
(UT)& ({\AA}) & {({\AA})} & {(sec)}\\
\hline
     1996/08/23&3620--4400&2.5&$4\times14$, 1200\\
     1996/08/23&4200--4980&2.5&10, $2\times7$, $2\times20$,$2\times600$\\
     1996/08/23&5200--6665&4.5&10, $2\times7$, $2\times20$,$2\times600$\\
     1996/08/23&6460--7930&4.5&$4\times14$, 1200\\
     1997/08/10&3310--3710&1.5&$2\times1200$\\
     1997/08/10&3710--4105&1.5&20, $2\times1200$\\
     1997/08/10&4110--4505&1.5&20, $3\times1200$\\
    1997/08/10&4510--4905&1.5&20, 25, 600, $4\times1200$\\
    1997/08/10&4910--5310&1.5&10, $2\times20$, 300, $4\times600$\\
    1997/08/10&5220--6220&2.5&20, $2\times1200$\\
    1997/08/10&6020--6800&2.5&10, $2\times20$, 300, $4\times600$\\
    1997/08/10&6770--7650&2.5&20, $3\times1200$\\
    1997/08/10&7620--8410&2.5&20, 25, 600, $4\times1200$\\
    1997/08/10&8370--9160&2.5&$2\times1200$\\
\hline\end{tabular}
\end{table}