If your website has this optional feature, you can schedule when the content will be published.

Publish On:

If this field is blank, you must manually publish the content, not to worry that is easy to do, and for most content types is the default option when you save the content.

If you enter a date and time, the article will be published at that time.

UnPublish On:

If this field is blank, you must manually unpublish the content, not to worry that is easy to do, but for most content types you do not want it to become unpublished automatically, anyway.

If you enter a date and time, the article will be unpublished at that time.

Note about automatic actions

The times for automatic actions is a request, but may not happen at exactly the time requested. There is a program that runs on the system to take care of these, and other, automatic tasks, it is called Cron. Every time a visitor loads a page, the system checks to see how long it has been since the last time Cron was run, if it has been longer than the interval set for your site (20 to 60 minutes, depending on what features are loaded) then Cron is run. Therefore, if you schedule something to be unpublished at midnight, but no one visits your site until 4AM, the automatic action will not take place until then.