there is a bug with the language component. To solve just add the following snippet of code in EFullCalendarHeart.php file.
find to
if ($this->themeCssFile) {
$this->options['theme']=true;
$cs->registerCssFile($assets.'/lib/'.$this->themeCssFile);
}
$js='$("#'.$this->id.'").fullCalendar('.CJavaScript::encode($this->options).');';
$cs->registerScript(__CLASS__.'#'.$this->id, $js, CClientScript::POS_READY);
then add it.
if ($this->themeCssFile) {
$this->options['theme']=true;
$cs->registerCssFile($assets.'/lib/'.$this->themeCssFile);
}
[b]if ($this->options['lang']) {
$cs->registerScriptFile($assets.'/fullcalendar/lang/'.$this->options['lang'].'.js');
}[/b]
$js='$("#'.$this->id.'").fullCalendar('.CJavaScript::encode($this->options).');';
$cs->registerScript(__CLASS__.'#'.$this->id, $js, CClientScript::POS_READY);
it solve this problem.