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

Use Time.deltaTime

seconds.Rotate( Quaternion.Euler(0,0,Time.deltaTime * secondsToDegrees).eulerAngles );