I'm currently working on a cool, new project. The goal of it is to create a hand painted scene that changes depending on the time of the day. By day I want the scene to look cute and cozy but by night I want the mood to change completely by changing the lights and the actual environment. Think cracks in windows, sudden writing on the walls and doors, plants withering and much more. Ideas are always welcome!  I have started by making the day and night cycle using blueprints. The cycle has 3 phases: day, normal night and a night with full moon. During these phases different things will happen in the environment. Normal nights and nights with full moon will look different from each other as normal nights will be less creepy than the full moon ones. As a user you can change the duration of the day using a slider. You can completely stop time or make time go as fast as you want.  To make the lighting in the scene a bit more interesting, I made a cloud system. This system consists of two different types of clouds. The flat clouds in the background and the actual meshes closer to the camera. Both types cast interesting shadows on the scene and move at a certain speed depending on the duration of the day. 

You can also check out my polycount thread for more work in progress shots:

And my article in 80 level about day and night in stylized scenes: