By default, the GroupID property is -1, which means that the time-zone is not assigned to any group. Use a positive value to assign the time-zone to a specific group. Use the Add method of the Groups collection to add new groups to the control. The DisplayGroupingButton property indicates whether the header of the date displays the grouping button. The list of available groups is displayed on a drop down panel, once the user clicks the grouping/filtering button. The GroupID property specifies the identifier of the group where the event belongs. If the control displays groups the GroupID property of the newly created event is automatically updated with the group where the event has been created. The AllowMoveEventToOtherGroup property specifies whether the user can move an event from a group to another at runtime.

The control displays groups if:

• ShowGroupingEvents property is True
• The Groups collection has elements. By default, the Groups collection contains no Group objects.
• The Groups collection contains visible groups ( Visible property on True )

The following screen shot shows time-zones on different groups: