Diarium version: 2.8.20.0
OS + version: Windows 11 version 21H2 (build 22000.438)
This is a very minor issue but I believe that a feature was present in earlier versions which is now missing.
I normally operate in Calendar-Day mode which displays a separate square for each day. Days containing entries are highlighted.
Clicking in the title area opens the Calendar-Month view which displays a separate square for each month. I believe that months containing entries were previously highlighted but this is no longer the case - they are all blank.
The same applies to the Calendar-Year view - no years are highlighted.