Fix datetime columns for TreeList

GUIs.Monitor/frmMonitor.vb

@@ -209,11 +209,8 @@ Public Class frmMonitor
                 ' Show all columns in DisplayColumns List
                 For Each oColumn In TreeListResults.Columns
                     oColumn.Visible = DisplayColumns.Contains(oColumn.FieldName)
-                    If oColumn.FieldName = "ADDED_WHEN" Then
-                        oColumn.Format.FormatType = FormatType.DateTime
-                        oColumn.Format.FormatString = "dd.MM.yyyy HH:MM:ss"
-                    End If
                 Next
+                GridBuilder.SetDateTimeColumns(TreeListResults)
 
                 Dim oStateColumn As TreeListColumn = TreeListResults.Columns.Item("STATE")
                 For Each oNode As TreeListNode In TreeListResults.Nodes