Change the end date of a promoted post via Stream Administration
Click the Settings Cog.
Select Stream Administration under Posts.
Hover over a post title and click the post options ellipsis.
Select Update Promotion Status.
Select a new date for the promotion to end and click Update.
Change the end date of a promoted post via the activity stream
Hover over the bullhorn icon and click the post options ellipsis.
Select Update Promotion Status.
Select a new date for the promotion to end and click Update.