Solves a wood calendar puzzle

I got one of these puzzles here: https://poodlepuzzle.com/products/daily-calendar-puzzle

And I wanted to see if I could write a script that could help me with solving them.

Running the code will solve it for the current day.

python3 main.py

You can set arbitrary dates using the select_day function.

Runs seem to take between a few second and up to 15 minutes for the few cases I tested it (on 2.4 GHz MacBook Pro).

There are plenty of ways to improve it and make it faster, but in order not to spend more time in improving the code than I would save running the improved code, I decided to put it out in the open, and to only work on improvements while I am waiting for results.