The initial installation of Angular already contains locale data for English in the United States (en-US). The Angular CLI automatically includes the locale data and sets the LOCALE_ID value when you use the --localize option with ng build command.
To manually set the runtime locale of an application to one other than the automatic value, complete the following actions.
@angular/common/locales/ directory.LOCALE_ID token.The following example sets the value of LOCALE_ID to fr for French.
import { LOCALE_ID, NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { AppComponent } from '../src/app/app.component';
@NgModule({
  imports: [ BrowserModule ],
  declarations: [ AppComponent ],
  providers: [ { provide: LOCALE_ID, useValue: 'fr' } ],
  bootstrap: [ AppComponent ]
})
export class AppModule { }    
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Licensed under the Creative Commons Attribution License 4.0.
    https://angular.io/guide/i18n-optional-manual-runtime-locale