I think the way I typically think about it is the course properties one will apply to the course and all those enrolled, think of it like global for the course. 
 

The validity setting is for the users you are actively enrolling in that moment, so you could have unique windows for every user enrolled in the course if needed. 
 

I vaguely remember @lrnlab did a post or answered a thread in details on combinations of settings and soft deadlines for different results but can’t seem to find, maybe he remembers. 

@Bfarkas 

If I understand you correctly, I should use the option under Advanced Settings > Time Options for the global setting and the initial assignment of employees. 

If we have a situation where other folks need the course, but their compliance window might vary from the global audience, I would use the enrollment option to enter a validity window that is different from the global settings. Does that sound correct?

Is the different window after the course level one? I think that is the only gotcha of that plan. If the course has expired at the course level I believe it is expired for all, but if you want a series of different windows that are within the course level one that should work. 

I added a start and end date to a demo course under Time Options. When I enrolled myself into the course, I did not see the specific dates for the validity window. That is the source of my confusion!

Right, because the validity is a user level thing only shown if a user has one specifically set, the course time options are a course level that applies across the board.

Makes sense. Thank you for clarifying. I sincerely appreciate it!