It's a pretty basic calendar from Roman times:

A parapegma was a stone tablet with movable pegs and an inscription to indicate the approximate correspondence between, for example, the rising of a particular star and the civil date. Because the calendar had to be changed regularly to keep the civil calendar in phase with the astronomical one, the parapegma had movable pegs which could be adjusted as necessary.

But what is interesting is the possibility of the same thing occuring in Ecuador before contact with the west!

Source: pakhomov.com