I agree wit Ric here, Its a self deity. You are your own God so you dont need teh man upstairs. Its giving in to your inner animal, There are no holy days as such but since its about self worship your own bday is specail.
Its not as bad as everyone makes it out to be. I have also done some reading on it and it seems quiet silly, Same with the Temple of Set, which was set up by a retired airforce pilot so he could avoid paying taxes and it took off