How can I listen for modal close event?

You would just do

// home.ts
// -------

postEvent() { 

  let modal = this.modalCtrl.create(AddEvent);

   modal.onDidDismiss(data => {
     // Do stuff with the data you closed the modal out with 
     // or do whatever else you need to.
   });

  modal.present();

}

You can find this in the docs.

You Just need to listen to the modal close event in your home.ts

// listen for close event after opening the modal
    postEvent(){
        let modal = this.modalCtrl.create(AddEvent);
        modal.onDidDismiss(() => {
        // Call the method to do whatever in your home.ts
           console.log('Modal closed');
    });
    modal.present();
}

`