Getting started with #gnuplot
▻http://math-blog.com/2008/06/08/getting-started-with-gnuplot
gnuplot is an excellent scientific package for visualizing data and plotting functions
How to handle time-based data with Gnuplot | TechRepublic
▻http://www.techrepublic.com/blog/opensource/how-to-handle-time-based-data-with-gnuplot/2671
The solution is to set the xdata and timefmt variables of Gnuplot, by adding these commands right before the plot instruction:
set xdata time
set timefmt “%Y%m%d”
Plotting Apache Activity from Apache Access LOG
▻http://plone.uconn.edu/workspaces/uits-linux/facts/gnuplot-tips