formatting clock display

[Jos Balka]

Hi team, 
Nice work :-)

Q: In the older kde versions, one could enter a custom time format for the 
digital clock in the desktop bar at the bottom of the screen. Now one can only 
select between predefined formats.
E.g. I'd like to see the name of the day in my clock display. (I work on  an 
irregular schedule so sometimes it is nice to have a reminder of what day it 
is. ) I have used this option for years. It looked something like: 
"Tue 2018-09-05".

Now there is no name of the day in the clock unless one uses the long format. 
But that format is overkill: it uses the long format for both the name of the 
day and the name of the month. Is there a way to get the nice abbreviated 
format back? Or is it hidden somewhere?

Thanks.
JB