Make enemy's speed faster through time

Hello guys!
I found this script from one of the questions here and it’s a simple one to let a game object follow your character:

var target : Transform; //the enemy's target
var moveSpeed = 3; //move speed
var rotationSpeed = 3; //speed of turning

var myTransform : Transform; //current transform data of this enemy

function Awake()
    myTransform = transform; //cache transform data for easy access/preformance

function Start()
     target = GameObject.FindWithTag("Player").transform; //target the player


function Update () {
    //rotate to look at the player
    myTransform.rotation = Quaternion.Slerp(myTransform.rotation,
    Quaternion.LookRotation(target.position - myTransform.position), rotationSpeed*Time.deltaTime);

    //move towards the player
    myTransform.position += myTransform.forward * moveSpeed * Time.deltaTime;


What I want though is to make the follower’s move speed increase by “1” after every 30 minutes. Is it possible? Are there other better scripts than the one above? Thanks.

Add a variable that sets a time limit, and then compare this time limit to the elapsed time since the game started. (60 seconds x 30 minutes = 1800).
And when that time limit is reached add to the speed variable, and add another 1800 to your time limit to make it wait another 30 minutes.

Someting like this:

    private var timeLimit = 1800.0f;
    function Update () {
    // your code here...
    if(Time.time >= timeLimit)
     // Add 1 to the moveSpeed...
     moveSpeed += 1;
     // make it wait another 30 mins...
     timeLimit += 1800.0;
     // more code here...

Good luck!