Something similar to f57v.

[eggyk]

Very interesting example!
I’ll jump ahead a bit: if this is a calendar, then it’s kind of strange, and it has too few words. Perhaps it’s an encryption disk styled to look like a calendar, or a very unusual calendar.

That depends on your definition of "calendar". Calendars aren't always list styles like the ones you pin up on the wall today to remember a date. There are many types of "calendar" for lots of purposes, in the form of grid tables and circular diagrams. They used similar diagrams for astrology, or for calculating easter etc.

Circular diagams, including those with concentric circles, are unbelieveably common to find. Like these from You are not allowed to view links. Register or Login to view.:
       
   

So in my opinion, a digram containing concentric circles is not not particularly related to VMS You are not allowed to view links. Register or Login to view. on its own. They are quite common. 

Circular digrams with 4 people in the center circle is a different story, though.