just checking in to see where things stand re the "minimalist calendar".
It seemed to me, after trying all the ones mentioned here (and a good many others) that ClassicCalendar from Wellcraftedsoftware was really the only one fulfilling the requirements, though not all of them.
I also wanted/needed the option to color-mark days (eg left-click->enter a note, right-click->different colormarks), which this program presently does not offer. I've written to the author. Unfortunately, no reply.
(As a matter of fact, *no* prog I've seen offers this in a simple straightforward manner, it's always, when available, tied to specific task categories)
Maybe one could take the ClassicCalendar framework as a starting point for your project, Mouser?
Thanks for further info and pointers