David Sader

Adds three more levels of privacy(visibility) to the Settings–>Reading page.
<ol>
<li>
Site visible to any logged in community member – “Network Users Only”.
</li>
<li>
Site visible only to registered users of blog – “Site Members Only”.
</li>
<li>
Site visible only to administrators – “Site Admins Only”.
</li>
</ol>
<a href="https://codex.wordpress.org/Create_A_Network" rel="nofollow ugc">Multisite</a> Network Admin can set an override on site privacy at “Network Visibility Selector” on Network Settings page
Multisite Network Admin can set privacy options at Network-Sites-Edit under “Settings Tab” as well.
Network Admin receives an email when blog privacy changes.
RSS feeds require authentication.
robots.txt updates accordingly.
Ping sites filters correctly.
Privacy status reflected in Dashboard “Right Now” box.
Uses WP3+ functions auth_redirect(), network_home_url(), and home_url() for SSL login redirects.
Login message has link to sign-up page of a “Network Users Only” blog or a link the blog admin email if user is logged in but not a member of a “Members Only” blog.
Localization ready.

More Privacy Options

Hi. 
Thanks for the great plugin. 
It works out-of-the-box in WP 4.9.8

Kudos!!!

Simple and elegant

Adds three more levels of privacy(visibility) to the Settings-->Reading page.

peter_gross

<h4>Privat auf Zeit (de)</h4>
Mit dem Plugin Private4Time kann ein Blog für eine einstellbare Zeit auf nicht öffentlich gestellt werden. 
Zu diesen Zeiten können sich nur registrierte Benutzer anmelden und den Blog besuchen. Beim Login kann eine selbst definierte Meldung angezeigt werden.
Damit sich in der öffentlichen Zeit keine Benutzer registrieren können, kann man (bei WordPress Multiple Blogs oder früher bei wpmu Installationen) das Registrieren neuer Benutzer auf dem eigenen Blog verbieten, obwohl der Site Administrator Registrieren erlaubt hat.
<h4>Private for time (en)</h4>
Private4Time makes your blog permanently or for a given time period private. 
This means, at the private time, only registered users can visit the blog when they login.
You also can dissallow people to register to your blog, even if the site administratior (at WordPress Multiple Blogs or older wpmu) has enabled registering to blogs. This works as well on single WP blogs.
Both features where made to give blog administrators a safe technical solution to be not public for a given time period.
<h4>Features</h4>
<ul>
<li>set blog permanent private</li>
<li>set blog private from time to time</li>
<li>define own login message</li>
<li>uses the time zone of wordpress settings</li>
<li>allow / dissallow user registration for the blog</li>
<li>useable for single and multible blogs installation, also older wpmu</li>
</ul>
<h4>Additional Information</h4>
<ul>
<li><a href="http://private4time.blog-me.de" title="private4time.blog-me.de" rel="nofollow ugc">Plugin URL</a></li>
<li><a href="http://software-regensburg.de" title="Author´s Website" rel="nofollow ugc">Author´s Website</a></li>
<li><a href="http://blog-me.de" title="blog-me.de" rel="nofollow ugc">Author´s Blogs</a></li>
</ul>
<h4>Languages</h4>
<ul>
<li>en_US (English) – standard</li>
<li>de_DE (Deutsch) – language file</li>
</ul>

Private4Time

Makes a blog private or not accessable for a time period. Allows and dissallows registering also in WP Multiple Blogs. Shows your own login message.

More Privacy Options vs Private4Time