The current version of jSunnyreports (1.3.1.x ) has an annoying bug. As soon as it hits 01-01-2012 you will probably see a lot of stacktraces while generating the graphs. This is because the directory “2012” will not exist.
When you get this error, just add the 2012 directory in your jSunnyreports generation folder.
This issue is also fixed in 22.214.171.124 Storm.