How to compared time spacing wanted with actual time elaspsed

I have an object moving accross the screen and ever 30 seconds i want the object to stop moving moving for 2-3 seconds and then start moving again. I have been trying to find a way to compare the time spacing i want with the actual time elapsed. But im coming up blank. I was using
the code

if(30 == Time.time)
  Object stop moving;

//thats only sudo code.

but that that dosent work becuase Time.time is read only. So i want to know if there is another command that i am missing that i can use to compare the time spacing i want with the actual amount of since the game started. or am i just going about this totally the wrong way.

You need to stock the time when your object starts moving :

var startTimer:float = Time.time;

And then in the Update() method, you can have :

if ( Time.time >= startTimer + 30 )

You also need to declare the function StopMyObjectFor :

function StopMyObjectFor(waitingTime:float)
    yield WaitForSeconds(waitingTime);
    // Now you start moving your object again here

    // now we need to start over the counter :
    startTimer = Time.time;

This is in Javascript of course.