[TYPO3-seminars] is it possible to change the order of the columns in list view and add new columns

[Typo3 Seminar Manager]

Thanks a lot for your help.
I used category für the weekdays and changed the html template.

Now I have the next question. Is it possible not to show the weekday if it 
is the same as in the previous row in the list. In the manual I found a 
function for a date field: omitDateIfSameAsPrevious.
Could I use this somehow?

Regards Heike