Edit in JSFiddle

// app/heroes/hero.component.ts

// избегайте

@Component({
  selector: 'toh-hero',
  template: `...`
})
export class HeroComponent {
  @Output() onSavedTheDay = new EventEmitter<boolean>();
}

<!-- app/app.component.html -->

<!-- избегайте -->

<toh-hero (onSavedTheDay)="onSavedTheDay($event)"></toh-hero>