Simple Countdown Script behaving strange on iOS [HELP]

I have a basic countdown script that I've used in the past in old Flash project. For some reason when I run it in an iOS app it behaves strange. I am also looking at the best approach to modify so I can set my countdown variable to accept a value such as  2:15  ( Two minutes & 15 seconds ) rather than just whole numbers.

The weirdness is that if I set it to countdown 2 minutes...  I can see the timer start at 2:00   .. but then it jumps to 1:57 and never shows  1:59  1:58

Here is my script... is there a better way to do this ?

As always .. any help is appreciated.

// I would like to be able to use values such as  2:15
var theTime:int = 2;
var endTime:Number = getTimer();

var countdownTimer:Timer = new Timer(1000);


countdownTimer.addEventListener(TimerEvent.TIMER, updateTime);

function updateTime(e:TimerEvent):void
{
  var timeLeft:Number = endTime - getTimer();
  var seconds:Number = Math.floor(timeLeft / 1000);
  var minutes:Number = Math.floor(seconds / 60);


  seconds %= 60;
  minutes %= 60;


  var sec:String = seconds.toString();
  var min:String = minutes.toString();
  

if (sec.length < 2) {
    sec = "0" + sec;
  }


  var time:String = min + ":" + sec;
  time_txt.text = time;
  

  if(minutes == 0 && seconds == 0){
   
   trace("TIME ENDED");
   
  countdownTimer.stop();
   
   } 
}


function resetTimer():void{

  endTime = getTimer();

  countdownTimer.reset();
  
}


function startTimer():void{

  endTime += theTime*60*1000;  //adjust endTime to 15 minutes in the future.
countdownTimer.start();
}