how to rotate cube smoothly

Hi guys i need to get cube rotate very smoothly but i'm failing to get this here is my code

using UnityEngine; using System.Collections; using System;

public class clockAnimator : MonoBehaviour {

 // Use this for initialization
 void Start () {
 
 }
 private const float 
     secondsToDegrees = 0.1f;
 public Transform seconds;

 // Update is called once per frame
 void Update () {
     DateTime Time = DateTime.Now;

     //seconds.localRotation = Quaternion.Euler(0f, 0f,(Time.Millisecond*-secondsToDegrees)*0.03f);
     seconds.localRotation = Quaternion.Euler(0,0,Time.Millisecond*-secondsToDegrees);
 
 }

}

Thanks in advance Gokul