Calendar, Historical Background
The Stories of Calendars: Their Origins, Their Uses, Their Abuses, and Their Changes
The calendar: Old Style, New Style, other styles
The calendar is a word that comes from Latin calendarium, or "account book", and is derived from calendae or "the calends", the first day of all of the old Roman months. This was the day on which accounts were due and on which the priests of Rome called the people together to proclaim (calare) that the new moon had been sighted.
If there is one thing that every man thinks how sublime it is, it is to know what time it is.
Sources of information for this page are located at this Calendars Bibliography Unit.