making a table fit on a page by moving it left

I have a table where the last columns fall off the page. Instead of making the text smaller I would like the table to not adhere to the margin of where it begins. I would like to move it to the left. I am using flushleft, which is not working. Here is the code:

\begin{figure}
\begin{flushleft}
\begin{tabular}{l|l|l|c|c|c|c|c|c|c|c|c|c|c|c|c|c|c|c|c|c|}
\multicolumn{21}{l}{a)text}\\ \hline
    & 1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 & 9 & 10& 11& 12& 13& 14& 15& 16& 17& 18& 19& 20\\ \hline
day1&9.2&8.6&8.1&6.3&7.7&7.3&8.0&8.4&5.9&6.8&7.3&7.6&9.0&7.4&6.6&7.0& 5.3&7.0&8.0&5.2\\
day2&6.7&6.9&0&7.0&0&8.1&9.0&6.1&0&6.9&0&7.3&7.8&5.3&0&8.9&0&8.4&8.4&7.5\\
day3&0&5.2&0&0&7.5&0&0&8.2&0&0&5.4&0&0&8.3&0&0&7.7&0&0&7.3
\end{tabular}
\end{flushleft}
\caption{\label{fig:text}text experiment}
\end{figure}

What can be modified? What possible solutions exist?