My god, a trick that actually works as described??? My god I feel like I did when I first got into
magic, not sure what happened the last ten years, but very very very very very very very very few
tricks work as advertised.
This one does exactly what it says it does.
As long as the number of letters comprising the name of each month is the same, though I highly doubt that. But with just a few tweaks in the setup, I believe you can customize it to fit with any language. But do note that the included diary might no longer be used in this case.