The CMS has the option to save a node as draft (visible only to site admins) or to specify a date on which the node will be published, or to specify a date on which the node will be unpublished.
To use these option, create or edit an existing node, and scroll down to Node status.
To save a node as draft, simply uncheck the Published checkbox.
To specify a publication start or end (or both) date, enter a date in the Publish start and/or Publish end fields. Make sure the Published checkbox is checked!
When a node is unpublished, queued or expired, it is only visible for administrators. This is denoted in the Node overview with corresponding icons. To preview an unpublished node, click the Eye button. You can recognize a unpublished node on the front-end by a red line at the bottom of the page.