Scheduling Page/Post/Custom Post Updates

Using the PublishPress plugin we will:

Go to the page/post/custom post.
Click New Revision.
Click Edit Revision.
Click on the post title.
Make the desired changes.
Set the publish date/time.
Click save as draft.
If the approve revision button does not highlight, refresh the page.
Click Approve Revision. The revision will publish on the date and time you specified.