A period of time, marking 1966 C.E. as Year One. This was devised by the author, philosopher, and Church of Satan founder, Anton Szandor LaVey. As confirmed by Magister Bill M., the New Year is not marked by Walpugrisnacht, but rather 01 January. It marks the Age of Fire and the Year of Satan. The numbers in the year are typically written in Roman Numerals.
Peter H. Gilmore was appointed head of the Church of Satan in XXXIV Anno Satanas, earning the title of Magus.