Takashi Murakami

If you are not logged in, it will not hide the current public posts. ( Only one generation, but allows the future of the article published. ) 
公開記事を更新（予約投稿）した状態であっても、..訪問者が予約投稿前の記事を閲覧できるようになる

Fixed Future Posts

Plug-in ( Fixed Future Posts ) for the WordPress.

maximevalette

contemplate

With the iCal Feeds WordPress plugin you can have an iCal feed to have your blog posts 
(past and future with a customizable secret parameter) in your favorite iCal software: Google Calendar, 
Outlook, Hotmail, iCal, Evolution…

iCal Feeds

Generate a customizable iCal feed of your present and future blog posts.

Fixed Future Posts vs iCal Feeds