public class EventExample : MonoBehaviour
{
    public delegate void ExampleEventHandler();
    public static event ExampleEventHandler OneDayPassed;

    public static void NextTurn()
    {
        // do stuff then send event
        if (OneDayPassed != null)
            OneDayPassed();
    }
}

public class EntityWatcher: MonoBehaviour
{
    void Start()
    {
        EventExample.OneDayPassed += this.PrepareNextDay;
    }

    public void PrepareNextDay()
    {
        // Do other stuff that happen after the day is done

    }
}

public UnityEvent whoa;

using UnityEngine;
using System.Collections;
using UnityEngine.Events;

public class BigScript:MonoBehaviour
    {
    [Header("Here's a cool event! Drag anything here!")]
    public UnityEvent whoa;
    }

public class BigScript:MonoBehaviour
    {
    [Header("Here's a cool event! Drag anything here!")]
    public UnityEvent whoa;

    private void YourFunction()
      {
      whoa.Invoke();
      }

whoa.AddListener(ScreenMaybeChanged);

...
using UnityEngine.Events;

// example, function has one float argument:
// ADD THIS at the top of the file:
[System.Serializable]
public class _UnityEventFloat:UnityEvent<float> {}

public class SimpleFingerResize : MonoBehaviour
{
    public _UnityEventFloat changedLength;
    public _UnityEventFloat changedHeight;

    ... and then ...

    void ProcessValues(float v)
    {
        ....
        if (changedLength != null) changedLength.Invoke(1.4455f);
    }
}