Alert Dismiss problem with ionChange: Ionic2-beta.11

Ionic Framework ionic-v3
1

Hello to everyone! I’ve an alert wich is fired on (ionChange) event like shown below:

<ion-datetime displayFormat="HH:mm"
                    [(ngModel)]="time"
                    (ionChange)="submitTime($event)"></ion-datetime>

submitTime() {
    let alert = this.alertCtrl.create({
      title: 'Time',
      subTitle: 'Your time has been submitted!',
      buttons: ['OK']
    });
    alert.present();
  }

When I click on ‘OK’ button, the alert isn’t dismissed. Have I done something wrong?