How to set up Approval mecanism

After installing the version 1.0.18 or bigger version, and after creating an event, space administrator can click checkbox to activate the approval for the current event and future ones.
Events created before 1.0.18, will appear always in Calendar and lists. For the events created after installing 1.0.18 or greater, will not appear if checkbox is checkd and if event is not approved. The event can be approved by clicking the button approve.