Is there a way to cast shadows for an object for the entire year all at once? or a Ruby script that could be written to do so?
Also I assume you mean shadows for the same time each month [or week] otherwise the overlapped shadows would become a ‘blob’?
There is some hope… perhaps you could make a series of scene-tabs for the 12 months’ shadows [using the same time and camera position] and export those as 12 images and then overlay them in an image-editor to get the desired effect ?
I have also made http://sketchucation.com/pluginstore?pln=TIG_shadowProjector
BUT these tools produce shadows casts for one sun in one scene etc.
You could have course ‘overlay’ several results, but I still think the scene-tabs >> images, which you then overlay in say Gimp is the sensible solution…
I find video presentations lead to far better viewer comprehension of shadows.
Shadows are never static. Still images fail to convey their fleeting nature.
Consider creating a scene for each month and then export a video.