The WORKDAY function in Excel works on my computer, but not on my boss' or our IT people's, even though we all run the same version. The IT person is "not sure" if that is the sort of feature you can option out during Excel's installation or Windows updates.
My boss and the IT person "think it's very interesting" that I can use this formula function and they can't.
by suddenly being the unofficial expert on the subject, and then getting into trouble when that subject goes wrong in the future. Even though they had nothing to do with it.