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.

timlinden

Remembering to post every day, and which days you already posted, is super easy with this plugin. 
It shows you a calendar with days red when there isn’t a post, and days green when there is. Green 
days you can hover over and see the title of the post, and click to edit the post for that day.

wpFutureCal

A simple calendar that displays when you edit posts, showing which days you have posted on.

Fixed Future Posts vs wpFutureCal