I use a different approach.

I have a nonbusiness dates control table where one first defines the general and specific nonbusiness dates wanted. Then you call a stored proc with a year range to gen the actual nonbusiness dates table. It gens 16 years in a sec or two. The tables have a FK relationship. While you could change the final dates table by hand, the idea is that you change the controls/definition and the gen the actual data, simply to cut down on errors.

If you'd genuinely interested in possibly using this approach, let me know and I can post the code.