2. Workaround

1. The service.ts

@Injectable()
export class TimeService { 
  // ... some useful stuff
  onDestroy(): void {        
    // ... some clean up logic
  }
}

2. The component.ts

@Component({/*... omitted for brevity*/})
export class TimeWidgetComponent implements OnDestroy{

  constructor(private timeService: TimeService) {
    // useful stuff using timeService
  }
  
  ngOnDestroy() {
    this.timeService.onDestroy();
  }
}