I'm trying to calculate the working hours between a lot of different dates.
I'm currently using the networkdaysfunction to exclude weekends and holidays.
I have two problems. Sometimes saturdays are used for working, how do I
include these? Usually, but not all the time, fridays are shorter (from 6:30
to 14:00 opposed to from 6:30 to 23:00). My current formula is only excluding
the hours from 23:00 to 6:30.

my formula

=(NETWORKDAYS(start date; end date ; holydaylist)-2)*16,5+((23:00-MOD(start
date;1))+(MOD(end date;1)-06:30))*24

Any help would be much appreciated.