Want a desktop calendar for your Windows 8?

It's easy.....

With Win-8's 'slideshow' style themes 'wallpaper', it's quite simple. Just find the calendar you like, then use your favorite graphics program to size it so that the pages are the full height of your screen's resolution, and then number the pages consecutively in a folder you made for them. 

Now, go in to that folder, and set it to display its contents as a slideshow. Before you actually start that, be prepared to use your screenshot-saving feature to capture an image of each of these calendar pages, using your Windows Key plus the Print Screen Key. Now, start your slideshow, and capture an image of each of its pages in turn as they change.

This will result in a set of images inside your Screenshots folder which will each have one page of your calendar centered on the page, with an automatically sized wallpaper the correct size for your screen. Just put those, in their correct order, into a folder named DesktopBackground, and then put that inside another folder named for whatever you wish to call your calendar's theme. 

Now, go into C:\Users\YourUserName\AppData\Local\Microsoft\Windows\Themes and using drag-and-drop, put your new theme's folder into that Themes folder. Then, open your new folder, open its DesktopBackground folder,
select all images, and then using your right-click menu on one of those, select to "Set as desktop background". This activates your new theme, and after that, you can use "Personalize" on your desktop's right-click menu to access the window for Personalization, in which you can save your new theme, and then set its configuration. If you don't want your calendar pages changing every few minutes, but would rather have only the present month continually shown, then remove the little check marks from the upper left corners of all your new images except for the one in the present month's image. That will in effect change your 'slideshow' theme into a one-image-only version, until you reconfigure it again.