Register the EventEmitter in your child component as the @Output:
@Output() onDatePicked = new EventEmitter<any>();
Emit value on click:
public pickDate(date: any): void {
this.onDatePicked.emit(date);
}
Listen for the events in your parent component's template:
<div>
<calendar (onDatePicked)="doSomething($event)"></calendar>
</div>
and in the parent component:
public doSomething(date: any):void {
console.log('Picked date: ', date);
}
It's also well explained in the official docs: Component interaction.