To understand how to defer an article to be published later, you must first understand the process for submitting an article.  Click Here for that FAQ.

When you arrive at the final step in publishing, you will be a Publish Later button. Next to that button, you will see a field labeled: "Click in this field to activate the date select widget"

By clicking in that field, a date widget will "popup" allowing you to select the date for which you want your article published. (To exit the date widget,  click the X on the widget.)

After closing the date and time widget, click the button that says:

Note: all dates and times are based on Central Time.

Once you press the Published As Schedule button, your article will be put in a deferred articles queue  to be published on the date & time you have scheduled. 

To review any deferred articles, you may login to your Profile pages and then press the My Articles Tab. On that page, you will see a button labeled "Manage Deferred." (If you do not have any deferred articles, you will not see the button.)

When you do have deferred articles waiting to be published, you may use that "Manage Deferred" button to further edit your content. Or you can choose to Publish immediately from there, if you wish.