Day and night cycle

Hello guys, so i thought it would be a good idea to make a simple day and night cycle however is there a way so when it is night it doesn't go completely black? Here is the script if you are interested

var cyclemins: float;
var cyclecalc: float;

cyclemins = 1;
cyclecalc = 0.1/cyclemins *-1;

function Update () {
transform.Rotate(0, 0, cyclecalc, Space.World);
}


Thanks.

 

What is that script doing?

 

If you add some ambient light to your scene in the Lighting window, you'll have a minimum amount of light even when objects don't receive direct lighting.