How Would I Change This To Read Within A Time Range?

I have this system time reference script that I would like to change so that instead of doing something on hour it did it within a time range say between 8:00 to 12:00 noon. How would I change the setting of this script so that it does that?

 void Awake () {
         if (sending == null) {
             DontDestroyOnLoad (gameObject);
             sending = this;
         } else if (sending != this) {
             Destroy (gameObject);
         }
         MessageCentreText.text = "CALIBRATE";
 
     //Time OF Day Notification
     //Noon Time
     if (sysHour == 12) {
         GetComponent<AudioSource>().clip = timeVoicesNoon[Random.Range(0,timeVoicesNoon.Length)];
         GetComponent<AudioSource>().Play();
             MessageCentreText.text = "GOOD AFTERNOON";
             Debug.Log ("Good Afternoon!");
     } 
     //Morning Time
     else if (sysHour == 8) {
         GetComponent<AudioSource>().clip = timeVoicesMorning[Random.Range(0,timeVoicesMorning.Length)];
         GetComponent<AudioSource>().Play();
             MessageCentreText.text = "GOOD MORNING";
             Debug.Log ("Good Morning!");
     }
     //Night Time
     else if (sysHour == 22) { 
         GetComponent<AudioSource>().clip = timeVoicesNight[Random.Range(0,timeVoicesNight.Length)];
         GetComponent<AudioSource>().Play();
             MessageCentreText.text = "GOOD EVENING";
             Debug.Log ("Good Night!");
     }
 
         else{
         //Do something if desired
             MessageCentreText.text = "KNIGHT INDUSTRIES 2000";
         Debug.Log("Go to bed!");
     }
 }