However, I had expected that this day and month in the format DD.MM. or perhaps DD.MM.YY. is displayed. In fact, however, the day of the week on the day (no leading zero for single-digit days) is displayed.
The weekday is therefore Mon / Tue / Wed / Thu / Fri / Sat / Sun appears as a three-digit abbreviation. There is no way on the German abbreviations or on a view with year switch. Only the color you can change.
Here more would have been a lot with very little effort in it ...