Acta Apostolicae Sedis (
Latin for "Acts of the
Apostolic See"), often cited as
AAS, is the official
gazette of the
Holy See, appearing about twelve times a year. It was established by
Pope Pius X with the decree
Promulgandi Pontificias Constitutiones (29 September 1908), and publication began in January 1909. It contains all the principal decrees, encyclical letters, decisions of
Roman congregations, and notices of ecclesiastical appointments. The
laws contained in it are to be considered promulgated when published, and effective three months from date of issue, unless a shorter or longer time is specified in the law.