Notes in Calendar

I think it would be great if you could add notes / events to the calendar.

No big connected functionality, just a visual thing that you see when opening the calendar.

I tried to visualize this idea in the attached image.

Example:

WWDC25 is coming up. I want to note that in the calendar so I don't schedule any posts during the keynote, because I'll likely post something about it in that time manually.

Also, I have another post scheduled regarding some Apple stuff, and I don't want to schedule it right after the event because it may no longer be relevant after the keynote.