calends

From Middle English calendes, calendas, calendis, kalandes, kalendas, kalendes, kalendez, kalendis, kalendus (also in the singular forms calende, kalend, kalende), from Latin kalendās, accusative plural of kalendae (“first day of a Roman month”), an archaic variant of calandae, from calandus (“which is to be called or announced solemnly”), the future passive participle of calō (“to call, announce solemnly”) (referring to the Roman practice of proclaiming the first days of the lunar month upon seeing the first signs of a new crescent moon), from Proto-Indo-European *kelh₁- (“to call, cry, summon”). Although the singular form calend (now obsolete, rare) appeared in English (and compare Old English calend, kalendus (“calends; a month”)), no singular form was used in Latin as recurring days of the calendar were always referred to in the plural. Sense 2 (“a day for settling debts and other accounts”) refers to the Roman practice of fixing the calends as the day for debts to be paid.