Expire Sticky Posts
This is a very simple plugin that will allow sticky posts (posts that you want to “stick” to the top of a page) to expire on their own. Once expired, they will move down the page to appear in reverse chronological order like any other post.
1. Go to Dashboard > Plugins to activate the plugin.
2. When you are in the post editor, you’ll see a new option appear in the Post Settings, at the bottom of the panel. Enter the date you want the post to become “unstuck,” or choose it from the pop-up calendar. The post will remain sticky until that date.
Looking for Classic Editor help? You can find it here: Expire Sticky Posts (Classic)