Format Tooltip in Angular Chart component

import { Component, OnInit } from '@angular/core';
import { ITextRenderEventArgs } from '@syncfusion/ej2-angular-charts';
import { Internationalization } from '@syncfusion/ej2-base';

@Component({
    selector: 'app-container',
    template:
    `<ejs-chart id="chart-container" [primaryXAxis]='primaryXAxis'[primaryYAxis]='primaryYAxis' [title]='title' [tooltip]='tooltip' (tooltipRender) = 'tooltipRender($event)'>
        <e-series-collection>
            <e-series [dataSource]='chartData' type='Line' xName='x' yName='y' name='India' width=2 [marker]='marker'></e-series>
        </e-series-collection>
    </ejs-chart>`
})
export class AppComponent implements OnInit {
    public primaryXAxis: Object;
    public chartData: Object[];
    public title: string;
    public marker: Object;
    public tooltip: Object;
    public primaryYAxis: Object;
    public tooltipRender(args: ITooltipRenderEventArgs): void {
        let intl: Internationalization = new Internationalization();
        let formattedString: string = intl.formatDate(new Date((args.point.x).toString()), { skeleton: 'MMMEd'});
        args.textCollections = formattedString;
    };
    ngOnInit(): void {
        this.chartData = [
             { x: new Date(2005, 0, 1), y: 21 }, { x: new Date(2006, 0, 1), y: 24 },
             { x: new Date(2007, 0, 1), y: 30 }, { x: new Date(2008, 0, 1), y: 38 },
             { x: new Date(2009, 0, 1), y: 54 }, { x: new Date(2010, 0, 1), y: 57 },
        ];
        this.primaryXAxis = {
           title: 'Year',
           valueType: 'DateTime'
        };
        this.primaryYAxis = {
           title: 'Efficiency',
        };
        this.marker = { visible: true, width: 10, height: 10, dataLabel: { visible: true}};
        this.title = 'Inflation - Consumer Price';
        this.tooltip = {enable: true}
    }
}

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { AppComponent } from './app.component';
import { ChartModule } from '@syncfusion/ej2-angular-charts';
import { GridModule } from '@syncfusion/ej2-angular-grids';
import { PageService } from '@syncfusion/ej2-angular-grids';
import { AccumulationChartModule } from '@syncfusion/ej2-angular-charts';
import { DialogModule } from '@syncfusion/ej2-angular-popups';
import { PieSeriesService, AccumulationTooltipService, AccumulationDataLabelService } from '@syncfusion/ej2-angular-charts';
import {
    LineSeriesService, DateTimeService, DataLabelService, StackingColumnSeriesService, CategoryService,
    StepAreaSeriesService, SplineSeriesService, ScrollBarService, ChartAnnotationService, LegendService, TooltipService, StripLineService,
    SelectionService, ScatterSeriesService, ZoomService, ColumnSeriesService, AreaSeriesService, RangeAreaSeriesService
} from '@syncfusion/ej2-angular-charts';

/**
 * Module
 */
@NgModule({
    imports: [
        BrowserModule, ChartModule, AccumulationChartModule, GridModule, DialogModule
    ],
    declarations: [AppComponent],
    bootstrap: [AppComponent],
    providers: [LineSeriesService, DateTimeService, ColumnSeriesService, DataLabelService, ZoomService, StackingColumnSeriesService, CategoryService,
        StepAreaSeriesService, SplineSeriesService, ChartAnnotationService, LegendService, TooltipService, StripLineService,
        PieSeriesService, AccumulationTooltipService, ScrollBarService, AccumulationDataLabelService, SelectionService, ScatterSeriesService,
        PageService, AreaSeriesService, RangeAreaSeriesService ]
})
export class AppModule { }

import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import { enableProdMode } from '@angular/core';
import { AppModule } from './app.module';

enableProdMode();
platformBrowserDynamic().bootstrapModule(AppModule);