defaultLocale property

String defaultLocale

The default locale. This defaults to being set from systemLocale, but can also be set explicitly, and will then apply to any new instances where the locale isn't specified. Note that a locale parameter to Intl.withLocale will supercede this value while that operation is active. Using Intl.withLocale may be preferable if you are using different locales in the same application.

Implementation 

static String get defaultLocale {
  var zoneLocale = Zone.current[#Intl.locale];
  return zoneLocale == null ? _defaultLocale : zoneLocale;
}
void defaultLocale= (String newLocale)

Implementation 

static set defaultLocale(String newLocale) {
  _defaultLocale = newLocale;
}