Juste set LOCALE_ID in your app.module.ts file :

import {NgModule, ReflectiveInjector, LOCALE_ID}      from '@angular/core';

@NgModule({
    imports: [
        BrowserModule,
        FormsModule,
        HttpModule,
        routing
    ],
    declarations: [
        AppComponent,
    ],
    providers: [
        {provide: LOCALE_ID, useValue: 'fr-FR'},
        BaseRequestOptions
    ],
    bootstrap: [AppComponent]
})