/**
  * Render time column
  * 
  * @param Varien_Object $row
  * @return string
  */
 public function render(Varien_Object $row)
 {
     if ($row->getTimeRange() == $this->__('Totals')) {
         return $row->getTimeRange();
     }
     $html = '';
     $requestData = Mage::helper('adminhtml')->prepareFilterString($this->getRequest()->getParam('top_filter'));
     switch ($requestData['report_radio_select']) {
         case 'hours_of_day':
             $html = $row->getTimeRange() . 'h';
             break;
         case 'days_of_week':
             $daysofweek = Mage::helper('inventoryreports')->getDaysOfWeek();
             $html .= $daysofweek[$row->getTimeRange()];
             break;
         case 'days_of_month':
             $html .= 'Day ' . $row->getTimeRange();
             break;
         case 'sales_days':
             $html .= Mage::getModel('core/date')->date('d/m/Y', strtotime($row->getTimeRange()));
             break;
     }
     return $html;
 }