Other creative calendars I have found

Unfortunately I cant find much about these as they were all from a long blog post that hasn't credited and of the sources of these.

This is a great idea, as far as I can tell you move the sleeve to set the correct days for each month

Nice layout.

cleaver idea, obviously mixing in the aesthetics of an eye chart.

This one is lovely, I found it on Behance: link

This one as well, great but far more 'illustratory' than my style, too many twiddly bits! link