I looked the follow post but I am still confused how to achieve what I want
We have a lot of part-time employees. Now most of them do not work full days and generally we do not care about on which days they work, we just care about their monthly/annual hours worked.
So in practice I just spread out the hours over the work week in the work schedule, with more hours on Thursdays since this is the day we all work in the office together.
So f.e. the 10% aka 4h per week work schedule is
Mon: 30min
Tue: 30min
Wed: 30min
Thu: 30min
Fri: 30min
But I think this messes up the vacation days.
We offer 25 days of vacation per year and our work week is 40h, so conversely someone working 10% should have 2.5 days, or 20h of vacation. But they end up with the full 25 days.
I did enable pro-ration on the entitlement as stated here: