Part-time "only X days a week" should be built in

[frabcus]

You can currently easily reduce the number of working hours in the day, but not number of working days in the week.

Two specific things:
a) extending "daily hours: variable, to also let us say days worked in the week
b) altering "holiday entitlement" for that case, as it is pro-rata at the moment, which is confusing (esp. as Salary isn't pro-rata) - realise this is more difficult