September. It's funny how we often think of September as back to school, but most kids I know start school in August. And the supplies needed for school were likely purchased earlier than that, in July. But that means that by now, that first, freshly sharpened pencil has grown a little dull.
If your computer's desktop is looking for some freshening up, try making it dull with the September Dull Pencil desktop wallpaper.