ScriptableRenderPipeline/SampleScenes/HDTest/GlobalIlluminationTest/TestRealtime.cs

using UnityEngine;
using UnityEngine.Experimental.Rendering;
using UnityEngine.Experimental.Rendering.HDPipeline;

public class TestRealtime : MonoBehaviour
{
    public GameObject m_SceneSettings = null;
    public float m_RotationSpeed = 50.0f;

    // Use this for initialization
    void Start()
    {
    }

    // Update is called once per frame
    void Update()
    {
        if (m_SceneSettings != null)
        {
            HDRISky skyParams = VolumeManager.instance.stack.GetComponent<HDRISky>();
            if (skyParams != null)
                skyParams.rotation.value = (skyParams.rotation + Time.deltaTime * m_RotationSpeed) % 360.0f;
        }
    }
}