Angular4(over2~)のロケールとPipe ref: https://qiita.com/Sekky0905/items/565060b4764eb4c68bec

app.component.ts

import {Component} from '@angular/core';

@Component({
  selector: 'app-root',
  template: `<p class="today">
本日は、{{today | date}} だ
</p>
`,
  styles: [`
.today{background-color:yellow}
`]
})
export class AppComponent {
  today = Date.now();
}

app.module.ts

import {BrowserModule} from '@angular/platform-browser';
import {NgModule, LOCALE_ID} from '@angular/core';
import {AppComponent} from './app.component';

@NgModule({
  declarations: [
    AppComponent
  ],
  imports: [
    BrowserModule],
  providers: [{provide: LOCALE_ID, useValue: 'ja-JP'}],
  bootstrap: [AppComponent]
})
export class AppModule {
}