day night cycle

I want to create a day-night cycle but when it is at the sun will move slower than when it is night how to do this in c#.

 

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class Sun : MonoBehaviour
{
public float DaySpeed = 2f;
public float NightSpeed = 15f;
// Update is called once per frame
void Update()
{
float speed;

if (transform.position.y >= -1.4)
{
speed = DaySpeed;
}

else
{
speed = NightSpeed;
}

transform.RotateAround(Vector3.zero, Vector3.right, speed * Time.deltaTime);
transform.LookAt(Vector3.zero);
}
}

this is the script

 

If you post a code snippet, ALWAYS USE CODE TAGS:

How to use code tags: https://forum.unity.com/threads/using-code-tags-properly.143875/

How to report your problem productively in the Unity3D forums:

http://plbm.com/?p=220

How to understand errors in general:

https://forum.unity.com/threads/ass...3-syntax-error-expected.1039702/#post-6730855

For something as complicated as a day/night cycle, probably best to start with tutorials. There are PLENTY:

 

You've stated what you want the script to do. You've posted a script which at first glance appears to do what you want the script to do. What you haven't done is actually stated a question.

 

This is our tutorial on creating a day and night system. Just angle the directional light so it's nighttime longer. Which will actually simulate what it's like in real life, since earth and any planet that will have seasons spins on an a tilted axis.