Live updating of an alert title with a property bound value

I’m trying to show an alert with a live update 10 sec countdown in the title.
But it only shows the initial value from when the alert is called.

Here’s the code:

// Class property
time:number;

// Method code

this.time = 10;

const that = this;
const alert = this.alertCtrl.create({
  title: this.time
});
const count = setInterval(function(){
  --that.time;
  if(that.time == 0){
    alert.dismiss();
    clearInterval(count);
  }
},1000);

alert.present();