I believe you are from one of the countries in the southern hemisphere, where we are a few days from the Winter Solstice. I think you might want to take a look at this page from the Satanic Rites and Celebrations section in the JoS:
https://web.archive.org/web/20111129231936/https://www.ageofsatan.co.cc/south_african_sabbat_dates_priestess_zildar_raasi.html
At the bottom, it says:
And Father Satan’s special day remains as the 23 of December throughout the world.
Good intention though, brother
Hail Father Satan!