What functionality is missing? What is unsatisfying with the current situation?

As a writer, I often have to think "what day of the week did this happen on, because that will affect what's going on around it?" Or, if I want something to happen on a particular day of the week, finding that month/year and the options of which dates fall on a Threesday isn't easy - I have to create a whole new article, import the BBCode for the calendar specifying that year, view the article and find the month/day(s) to get that query answered, all while I'm trying to write my narrative.  

How does this feature request address the current situation?

Being able to display my calendar in an article and enter/change a year in the "As of the year >Enter it here<" place would let me make just ONE calendar display article, and hop around as needed to see what days go with what dates.    

What are other uses for this feature request?

If you really wanted to think big, you could link items from Timelines that have a full Y/M/D date format to the relevant calendar and it would be a great way to see "what happened on this day?"