javascript drops over 30 fps

Is here something to do with this script. It lags very much and drops over 30 frames. It is day and night script what calculates time, moves sun etc.

 #pragma strict
 public var Sun : Light;
 var stars : GameObject;
 public var secondsInFullDay : float = 120f;
 public var currentTimeOfDay : float;
 public var timeMultiplier : float = 1f;
 var sunInitialIntensity : float;
 
 function Start () {
     sunInitialIntensity = Sun.intensity;
 }
 
 function Update () {
     UpdateSun();
 
     currentTimeOfDay += (Time.deltaTime / secondsInFullDay) * timeMultiplier;
      if (currentTimeOfDay >= 1) {
         currentTimeOfDay = 0;
     }
 }
 
 function UpdateSun(){
     Sun.transform.localRotation = Quaternion.Euler((currentTimeOfDay * 360f) - 90, 170, 0);
     var intensityMultiplier : float = 1;
      if (currentTimeOfDay <= 0.23f || currentTimeOfDay >= 0.75f) {
             intensityMultiplier = 0;
         }
         else if (currentTimeOfDay <= 0.25f) {
             intensityMultiplier = Mathf.Clamp01((currentTimeOfDay - 0.23f) * (1 / 0.02f));
         }
         else if (currentTimeOfDay >= 0.73f) {
             intensityMultiplier = Mathf.Clamp01(1 - ((currentTimeOfDay - 0.73f) * (1 / 0.02f)));
         }
 
         if(currentTimeOfDay < 0.197636){
             stars.SetActive(true);
         }
         if(currentTimeOfDay > 0.197636 && currentTimeOfDay < 0.7762121){
             stars.SetActive(false);
         }
 
         if(currentTimeOfDay > 0.7762121){
             stars.SetActive(true);
         }
  
         Sun.intensity = sunInitialIntensity * intensityMultiplier;
 }