[fw-mvc] Zend_Dojo & I18N

I'm trying to setup I18N for Zend_Dojo namely for elements of
Zend_Dojo_Form like drop-down calendar of DateTextBox etc.

My steps are:

1) In the layout script:
$this->dojo()->setDjConfigOption('extraLocale', 'fr-fr')
->requireModule('dojo.i18n');

Nothing happened. The calendar's month name and week names are in English still;

2) Add 'locale' to the form element declaration:
$this->addElement(
'DateTextBox',
'foo',
array(
'decorators' => $this->elementDecorators,
'label' => 'Date',
'required' => true,
'invalidMessage' => 'Invalid date specified.',
'formatLength' => 'long',
'locale' => 'fr-fr'
)
);

Nothing is changed still. The calendar's locale is en_US still.

Also, in the Dojo Internationalization manual written that Dojo has
dojo.requireLocalization() which is used to declare usage of I18N
resources and load them. I haven't found a corresponding method in
Zend_Dojo package.