You can schedule blog posts to automatically publish themselves at any time in the future. In the Publish module to the right of the post editor, click Edit next to “Publish immediately.”
Time and date fields will display; enter your desired time and click OK. The Publish button will change to Schedule. At the exact date/time you set, your post will automatically be published for visitors to see.
Un-scheduling a Post
If you’ve scheduled a post to be published in the future, but changed your mind and want to publish it immediately, head back to the Edit Post page for your scheduled post.
In the Publish module, click on the “Edit” link next to the date you had scheduled for your post.
Then enter today’s date and the current time as your scheduled post time and click “OK.” Click on the “Schedule” button, and your post will be published immediately.