Can I review events before they go public?

Yes. On one calendar, open Settings and set Contributor changes to Review before public, then click Save settings. Use the school default follows the school wide setting, and Publish instantly skips review. To set it for every calendar, use the Settings section at the bottom of the main Calendar page, pick Review before public, and click Save default. New events and changes from a Publisher then wait as pending review. They show under Needs you, where you click Approve or Reject. Nothing shows on the public calendar until you approve it. Editors, calendar owners, and admins always publish directly.