title: Why do Angular Locale defintiition files do not match locale identifiers for registerLocaleData
body: <p>I am trying to call RegisterLocaleData with locale data dynamically loaded from angular framework using locale identifiers but have been unable to do this due to framework naming conventions.</p>
  <p>I have written a function like:</p>
  <pre><code>public importLocaleDataAndSetLocaleFor(locale: string): Promise&lt;void&gt; {
     return import(`@angular/common/locales/${locale}.js`)
        .then((localeModule) =&gt; {
            registerLocaleData(localeModule.default, locale);
     });
  }
  </code></pre>
  <p>When the locale Identifier is 'en-GB' then it will successfully work. (file exists)
  When the locale identifier is 'de-DE' then it will not. (file not exists)</p>
  <p>Why do the locale files not exist for these locales in the Angular framework? It seems wrong/unusal given the identifiers are a standard.</p>
  <p>Surley there should be a file for common/locales/en-gb</p>
  <p>Surley there should be a file for common/locales/en-US</p>
  <p>Surley there should be a file for common/locales/de-DE</p>
  <p>But there are files for common/locales/en.js but that doesn't make sense. How can a locale file have a language but no region?</p>