//Lag modal component/page som heter Modal. new-room.page er parent page

//modal.component.ts

export class ModalComponent implements OnInit {
  dateMulti: string[];
  @Input() dates: [] = [];
  type: 'string';
  optionsMulti: CalendarComponentOptions = {
    pickMode: 'multi'
  };

  constructor(public modalCtrl: ModalController, private navParams: NavParams) {
    this.dateMulti = navParams.get('dates');
  }

  ngOnInit() {}

  dismiss() {
    this.modalCtrl.dismiss({
      'dismissed': true,
      data: {
        datesFromModal: this.dateMulti
      }
    });
  }
}


//modal.component.html

<ion-calendar [(ngModel)]="dateMulti"
              [options]="optionsMulti"
              [type]="type"
              [format]="'YYYY-MM-DD'">
</ion-calendar>
<ion-button (click)="dismiss()">CLOSE</ion-button>

//new-room.page.ts

private dates = [];
async presentModal() {
    const modal = await this.modalCtrl.create({
      component: ModalComponent,
      componentProps: {
        dates: this.dates
      }
    });
    await modal.present();
    const { data } = await modal.onWillDismiss();
    this.dates = data.dataFromModal.dates;
  }

//new-room.page.html

<ion-button (click)="presentModal()"></ion-button>