Something like that. But you'll dig this one. No sacrifice involved for a reading, promise.

[ He's far too casual with that joke as he tosses him a toothy little grin. But he taps the circle containing the glyphs. He actually taps at a glyph that's associated with him, but it's not like Ratio knows that. ]

It's a calendar. Simple version of it, since I can only do so much with paper and a pencil, but works well enough. Every day is unique and important, so the calendar of the Azteca reflects that.

[ And by giving it a closer look now that Ratio knows that, he might have some idea of how the circles are meant to work. The circle with dots has thirteen possibilities, and the other circle has twenty glyphs. Rotating one would rotate the other, and you get a unique combination of dots and glyphs because of how the numbers don't match. That said, it also wouldn't add up to the 365 days that Ratio has become familiar with on Earth, so maybe there's more to it. ]

I'm a god of divination, so can give a fortune based on where your day falls in the tōnalpōhualli.