I believe this has been discussed elsewhere on this forum, however I haven’t seen this fascinating topic much in the forum or, for that matter, anywhere!
I learned it from Greymatters; it’s a great description. If you haven’t seen it, check it out!
I’m just curious, have you guys learned and practiced this feat? If so, what do you think of it? If not, why on earth not?!? 
Is this the one?
Edit: related thread: Estimate Moon phase for any date
Yes that is the one; my apologies for not putting it in my message. Since I’m kinda new here, how does one go about putting in a link like you did for a site?
If you paste a link it will usually create a preview. You can link text by highlighting the text and clicking the editor icon that looks like a chain link.
Links can also be manually formatted like this, if you’re familiar with markdown:
[link text](https://artofmemory.com/)
There’s more information here: How to format text in the forum
You don’t need to remember all that information though — the simplest way to create a link is to just paste the URL into the post editor.
Thanks so much I really appreciate it
Perhaps a touch late, but I think this is seriously cool. I’m totally going to do this.
I actually want to do something slightly different with it. I want to combine the moon phase with the sidereal month/year. Sorta just have a basic idea of the current celestial “landscape” at all times. I was originally thinking of creating something similar to the runic calendar. Then maybe use it as part of a remember-every-day style practice.
Unfortunately I have no idea how to go about building something like this at present… But this link will help immensely thanks!