Google spreadsheets have a function called NETWORKDAYS(start_date, end_date,[holidays])
So you basically make a row/column with dates. I did a full year with Jan 1st … Dec 1st and then
=NETWORKDAYS(<month cell>,EOMONTH(<month cell>,0))
Doesn’t take everything into account, but for simple stuff it works.
So I calculated my pay – and now I’m just sad …
Have a nice weekend.