How to turn off all the built-in holiday notifications in my Calendar?

I want to turn all holiday notifications off for good. Not all my calendar notifications, just the built-in holidays.

Here are my settings for alerts within Calendar, but even though I have them turned off here, this is not working.

I can't find any solution on the web surprisingly, and the other person who posted about this was instructed to turn off notifications for calendar altogether, and obviously that is not a viable solution.

[Re-Titled By Moderator]