Here is a skeleton 2015 calendar created for Adobe Illustrator. I have previously posted an entry about trying to download a Calendar template for Adobe Illustrator CS2. I have found that many of them are either not suitable for starting out your own design from scratch or it is for higher versions of Adobe Illustrator. I know that many like me are searching for calendar templates for their new projects and probably do not have the latest Illustrator versions to open the available templates out there.
