Why is the ninth month called September?
1550s, from Old French prophanation (15c., Modern French profanation) or directly from Late Latin profanationem (nominative profanatio), noun of action from past participle stem of profanare (see profane (adj.)).
originally, the theft of something sacred; as early as the 1st century BC, however, the Latin term for sacrilege came to mean any injury, violation, or profanation of sacred things. Legal punishment for such acts was already sanctioned, in the Levitical code of ancient Israel. The Israelites had extensive rules to safeguard what was holy or consecrated, violation of which (especially of temple laws) often led to mob violence.