Read detailed use case. (Long post ahead)
I tend to work on different creative projects. I also include personal tasks, hobbies, and events in my calendar, so I can look back and see where my time went. Because of the huge variety in task types, it’s important for me to differentiate them with colors, so I can see in a month’s view what type of project is taking over and adjust accordingly (by drag and drop) if needed.
Sample calendars (Asana, ClickUp) to demo how I color code based on task types — various colors for projects, transparent or gray for personal tasks/events and reminders
I start by having a project page listing my tasks (preferably with nesting), then I group it together and divide harder tasks into smaller subtasks. This is usually in List View or Kanban. Then the Calendar is for checking if the assigned schedules fit in with everything else.

Kanban with parent and children tasks in Asana
Mockup of how I’d prefer it organized in Anytype
After that, the Calendar becomes my main view. (An inline calendar would be nice because it’s definitely going in my dashboard.)
In Asana, done tasks are faded out. In ClickUp, they have statuses that you can customize and assign colors. I always assign deeper colors for to-do and ongoing statuses, and their lighter versions for done statuses.
For this to happen in Anytype, ideally there’d be a color picker where you can input hex codes. Or at the very least, the vibrant colors should not be exclusive to texts and the lighter ones to backgrounds. I’d use it the other way and assign the vibrant ones as background for my to-dos, then the lighter ones for my completed tasks.

Color picker in CU
Side note:
I never archive tasks because I don’t want completed ones disappearing in view. I may re-home it in a different Set in Anytype, but I’d like all tasks to remain visible in Calendar.
Other things that would be convenient to have:
- Tasks that span multiple days connected in calendar
- Scrolling option available so you can still see the surrounding dates when it’s nearing the end of the month
- A start and end time that is both optional, so I can still record the time even when I forgot to add one of the two.
- Maybe have an option to display a few things
- An icon to express priority or style an event
- The parent task or a group/tag relation
- Graph displaying progress (I find it highly motivating)
- If it’s not asking too much… Recurring tasks that can be either fixed date or triggered when the current task is marked done. (I mostly use monthly, quarterly, and yearly.)
Last but not the least, my biggest pain point that a LOT of calendars overlook: Desktop Month View in mobile
Don’t know if there’s a term for this, it’s when the month view and its tasks in desktop are still visible in mobile without having to individually click dates to display tasks.
This is a huge dealbreaker for me. I don’t believe it’s a case of lacking screen real estate, as I’ve seen some apps do it. (They’re just not PKM apps.) I’d be truly grateful if you can find a way to incorporate this layout choice, so I can end my calendar hunt and camp all of my digital life here in Anytype. 
See how bad it is in my color-dependent use case…
In Asana and Notion:
I think these dotted numbers are the norm in mobile calendars, but in all honesty, I find them pointless.
All they do is tell me I have tasks, which I already know. And if I need to rearrange schedule while away from laptop, I’d have to click every single day to see what’s in it. (I rarely use Weekly View because some tasks could take days to finish, so I can’t visualize it properly by just looking at Daily or Weekly.)
Side Note:
Reading comments, I see now that this is good for daily note-taking, which isn’t my use case. 
For inspiration
Google did it right with their Month View layout. Unfortunately, I’m not a fan of everything else. (Slashed tasks, lack of task manager, among other things.)
Another example is Samsung. I really love how they did it. (You pull downwards to expand.) I understand this layout may not be for everyone, so I appreciate that they designed something that could work for different types of users.
Hold and slide for multiple days
I also love how the colored lines stack. Way better than dots, in my opinion.
I’m not expecting a duplicate design. A “basic” and “full” month view could work, too. Or a settings for everything you want to hide/see. I trust the devs to figure out what works best. 
That’s it. Thank you for considering my use case!