Anno Societatis
In the Society for Creative Anachronism, there is a special calendar counting years from the date the SCA was founded in 1966. Years are expressed as "Anno Societatis" (or "A.S.") followed by a number, usually expressed in Roman numerals. "Anno Societatis" is Latin for "in the Year of the Society." "Societatis" may be pronounced Sow-see-uh-TAH-tiss, Sow-key-uh-TAH-tiss or Sow-chee-uh-TAH-tiss.
The SCA's "New Year’s Day" is May 1st, the day that the First Tournament was held in 1966.