The Christian Calendar
The “Christian calendar” is the term traditionally used to designate the calendar commonly in use, although it originated in pre-Christian Rome.
The Christian calendar has years of 365 or 366 days. It is divided into 12 months that have no relationship to the motion of the moon. In parallel with this system, the concept of “weeks” groups the days in sets of 7.
Two main versions of the Christian calendar have existed in recent times: The Julian calendar and the Gregorian calendar. The difference between them lies in the way they approximate the length of the tropical year and their rules for calculating Easter. But the Julian and Gregorian calendars inherited a lot of their structure from the ancient Roman calendar. Therefore a study of that calendar is also relevant here.
The Calendar FAQ divides the description of the Christian calendar into these sections:
- The Roman calendar
- The Julian calendar
- The Gregorian calendar
- Counting years
- The Julian Period
- Week-related questions
- Miscellaneous questions