Hey

I know you can use for this the nice shader of Shadmar, but now if you want to try something else,

This is somewhat like you can obtain if you use a big light sphere rounding around the player. I speed up the cycle quicker for the video to see all the day/night.

I used the directional light rotation for the shadows, the color of the sky-sphere for the colorourfull effect and the color of the directional light for the luminosity, getting the no shadow night light.

Clouds/rain has been hidden to see better.

Here is a demo: