I think Thom's advice still stands. The only differences would be minor. You essentially want to cross join the two sets (People, Calendar).

SELECT p.PersonID, c.CalendarDate
FROM...

One day I swear I'm going to learn how to read. Apparently it hasn't happened yet.

If you're always "pointing at" or comparing to a date a fixed "distance"...

Is this a SQL Server question or an Access question? Using parameters in SQL Server, in my opinion, is MUCH clearer. 
Given the syntax and the absolutely screwy way Access...

You should read Jeff Moden's article about Tally Tables. They're super useful once you understand how to use them

Can't you check the Parameters.Count property to see how many items are selected and use that to determine whether an object is visible?  Something like

Ctl.Visible = (Parameters.Count>=2)

You can't upload/serve SSRS 2016 reports on SSRS 2012.

Welcome aboard. 
What we're asking for is a create table script and some insert statements.... something we can run so we have some data to work with.  Since you're new...

I learned Access first, and the whole mutant query engine/VBA thing was just weird.

Amen to that. I think the querying capability in Access is meh on a good day. I was asking originally because I was looking at a job posting where I...

Thanks Eirikur. I considered that... just seems there really isn't a good lightweight way in Access. =(

I wish there were an equivalent to ROW_NUMBER() in Access. Sooo handy in SQL Server!  Thanks!