Index: branches/RC/core/units/general/cat_tag_processor.php
===================================================================
diff -u -r8929 -r8991
--- branches/RC/core/units/general/cat_tag_processor.php	(.../cat_tag_processor.php)	(revision 8929)
+++ branches/RC/core/units/general/cat_tag_processor.php	(.../cat_tag_processor.php)	(revision 8991)
@@ -458,6 +458,60 @@
 
 			return preg_replace('/('.implode('|', $keywords).')/i', $opening.'\\1'.$closing, $ret);
 		}
+
+		/**
+		 * Returns last modification date of items in category / system
+		 *
+		 * @param Array $params
+		 * @return string
+		 */
+		function LastUpdated($params)
+		{
+		    $category_id = $this->Application->GetVar('m_cat_id');
+		    $table_name = $this->Application->getUnitOption($this->Prefix, 'TableName');
+
+			if (isset($params['local']) && $params['local'] && $category_id > 0) {
+				// scan only current category & it's children
+		        $sql = 'SELECT TreeLeft, TreeRight
+		        		FROM '.TABLE_PREFIX.'Category
+		        		WHERE CategoryId = '.$category_id;
+		        $tree_info = $this->Conn->GetRow($sql);
+
+		        $sql = 'SELECT MAX(item_table.Modified) AS ModDate, MAX(item_table.CreatedOn) AS NewDate
+		        		FROM '.$table_name.' item_table
+		        		LEFT JOIN '.TABLE_PREFIX.'CategoryItems ci ON (item_table.ResourceId = ci.ItemResourceId)
+		        		LEFT JOIN '.TABLE_PREFIX.'Category c ON c.CategoryId = ci.CategoryId
+		        		WHERE c.TreeLeft BETWEEN '.$tree_info['TreeLeft'].' AND '.$tree_info['TreeRight'];
+		    }
+			else {
+				// scan all categories in system
+				$sql = 'SELECT MAX(Modified) AS ModDate, MAX(CreatedOn) AS NewDate
+		       			FROM '.$table_name;
+		    }
+
+		    $row_data = $this->Conn->GetRow($sql);
+		    if (!$row_data) {
+		    	return '';
+		    }
+
+		    $date = $row_data[ $row_data['NewDate'] > $row_data['ModDate'] ? 'NewDate' : 'ModDate' ];
+
+		    // format date
+		    $format = isset($params['format']) ? $params['format'] : '_regional_DateTimeFormat';
+		    if (preg_match("/_regional_(.*)/", $format, $regs)) {
+				$lang =& $this->Application->recallObject('lang.current');
+				if ($regs[1] == 'DateTimeFormat') {
+					// combined format
+					$format = $lang->GetDBField('DateFormat').' '.$lang->GetDBField('TimeFormat');
+				}
+				else {
+					// simple format
+					$format = $lang->GetDBField($regs[1]);
+				}
+			}
+
+			return adodb_date($format, $date);
+		}
 	}
 
 ?>
\ No newline at end of file