I work in the events industry.
So I have a top-level board that is our season calendar. And then a board for each of our events with all the elements needed to bring the event together.
I use dependencies on the event boards so that items happen a certain number of weeks from the event date. (event dates frequently change and so all the deliverables have to change due dates too)
Ideally what I would like to be able to do is update the event date on the top-level calendar - and then have the dates automatically update in the event boards - but I can’t figure out how to do this.