Each semester I have to calculate what we call a 60% rule for withdrawal from
classes. I figured out the simple part of the formula (start date x .60
(plus the start date for the actual date)

My question is: How can I leave out certain weekends and holidays? I tried
using the WORKDAY or NETWORKDAYS formula without success. This would actually
a day or two on the result in some cases.

The other formula that could use help is the one that adds 3 days or 5 days
to the start date of a class NOT including weekends and holidays.

This is probably easy for most of you, but until now, I have only used Excel
more for information management and not calculations (or only simple ones)

Thank you in advance.