All content blocks would have options to "publish" or "save draft." The "publish" option would include a date selector with current date as its default.
Save Draft
If users chose "save draft" then the content block will NOT be displayed in view mode. In edit mode, the content block will be displayed along with a marker that indicates its publication status ("not published")
Publish with publication date
If users chose "publish" and set a date in the future, then the content block will NOT be displayed in view mode until that date. In edit mode, prior to the publication date, the content block will be displayed with a marker that indicates its publication status (" publish on <<publication date>>")
Other modifications
Functions checking for view authorization would need to be modified to check publication status and date.
This feature would provide similar functionality to "Activation Dates/manual setting" (1820843).