Is it possible to preview a Calendar Event page without publishing it? If so, how do I do it?
Although there is no Preview button, you can publish the event privately so that the event is not published to the event calendar. Only those with the specific private URL can get to the event to review the content and look. Once the event needs to go live, you can publish the event publicly.
To publish the event:
Select Content > Events
Click Edit on the event
Select either radio buttons for Published (Public) or Published (Private)