code: public static void init(Context context) {
          if (sInitCalled) {
              return;
          }
  
          sInitCalled = true;
  
          try {
              DateTimeZone.setProvider(new ResourceZoneInfoProvider(context));
          }
          catch (IOException e) {
              throw new RuntimeException("Could not read ZoneInfoMap. You are probably using Proguard wrong.", e);
          }
  
          context.getApplicationContext()
              .registerReceiver(new TimeZoneChangedReceiver(), new IntentFilter(Intent.ACTION_TIMEZONE_CHANGED));
      }
docs: Initializes ResourceZoneInfoProvider and registers an instance of
  {@link TimeZoneChangedReceiver} to receive android.intent.action.TIMEZONE_CHANGED
  broadcasts. This method does nothing if previously called.