I think I'll just call it calendar. There's another calendar tool from openbsd, but I think this one fits the name better and when porting to openbsd it can just be renamed to vcalendar or calendar-kota or something.

I could start by simply cloning the look of the cal program, but in a tui in which you can use the mouse or vim-like binds to move between the days, months and years.

     August 2022
Su Mo Tu We Th Fr Sa
    1  2  3  4  5  6
 7  8  9 10 11 12 13
14 15 16 17 18 19 20
21 22 23 24 25 26 27
28 29 30 31

My idea is that when you click or press enter on a particular day it will open your text editor (similar to how aerc works) from right inside this tool. The exact file path that opens will be configurable. For example I'd like mine to open one of the date entries in my memex such as 2022-08-04 which is stored in ~/docs/memex/journal/2022-08-04.md. I can use go's templating and date formatting features for that.

My other thought is that this program should as much of the screen as is available. If you have more vertical space it will show the previous and next months stacked on top of each other, but in the lighter grey color. Additionally, if you have more horizontal space it could show a preview of the selected date's entry off to the right side. Perhaps something like this:

       July 2022
 Su Mo Tu We Th Fr Sa
                 1  2    Fortunately, I was only about 50 minutes late. We began
  3  4  5  6  7  8  9    in an intense battle with one of those spooky shadowy
 10 11 12 13 14 15 16    cats that captured [/moxie/finn](/moxie/finn.html) last session was
 17 18 19 20 21 22 23    fighting with the rest of the group when I came through
 24 25 26 27 28 29 30    the portal.
 31
      August 2022        During the battle the cat seemed to summon these creepy
 Su Mo Tu We Th Fr Sa    tall grey men that charged at us, it was quite an
     1  2  3 [4] 5  6    intense fight and although we survived we're beaten
  7  8  9 10 11 12 13    bloody and will need a few days of rest to heal up.
 14 15 16 17 18 19 20
 21 22 23 24 25 26 27    Despite our injuries finn encouraged the rest to quickly
 28 29 30 31             look at the magic circle down beyond the alter's portal.
                         I was lowered on a rope by //moxie/gordon, but we
    September 2022       expected the room to be upsidedown as it was. For
 Su Mo Tu We Th Fr Sa    whatever reason it was no longer upsidedown and I
              1  2  3    dropped from the ceiling and nearly slammed into the
  4  5  6  7  8  9 10    floor. It was very unexpected and really knocked the
 11 12 13 14 15 16 17    wind out of me.
 18 19 20 21 22 23 24
 25 26 27 28 29 30