'Time Planner' window mode.
Present items containing 'date/time' tags in an 'agenda' or 'calendar' view. Tagspaces as a weekly planner!
The idea is to leverage date/time tags with an extension to the existing Smart Tag system (which is already good and should remain).
When I create a note or download a file that I want to work on next Tuesday, for example, I could tag with the date and the time (and possibly a duration, such as '2 hours').
Then I could click on 'agenda' and view a 5 or 7-day calendar-style planner, where I can scan all of the items that I've scheduled (using smart tags) for the week, and adjust things around as needed. This way I can dynamically plan how I spend my time!