Why Easter Sunday Falls on a Different Day Each Year | Print |  E-mail
User Rating: / 0
PoorBest 
Tuesday, 03 April 2012 15:24


04042012WESF


Though Easter is an annual festival observed throughout the Christian world, the date for Easter shifts every year within the Gregorian Calendar, the standard international calendar which regulates the ceremonial cycle of the Roman Catholic and Protestant churches.

The current Gregorian ecclesiastical rules that determine the date of Easter trace back to 325 AD at the First Council of Nicaea convened by the Roman Emperor Constantine. At that time the Roman world used the Julian Calendar, put in place by Julius Caesar.


The Council decided to keep Easter on a Sunday, the same Sunday throughout the world. To fix incontrovertibly the date for Easter, and to make it determinable indefinitely in advance, the Council constructed special tables to compute the date. Nonetheless, different means of calculations continued in use throughout the Christian world.


In 1582 Pope Gregory XIII completed a reconstruction of the Julian calendar and produced new Easter tables. One major difference between the Julian and Gregorian Calendar is the “leap year rule.”


Universal adoption of the Gregorian calendar occurred slowly. By the 1700s, most of western Europe had adopted it. The Eastern Christian churches still determine the Easter dates using the older Julian Calendar method.


The usual statement, that Easter Day is the first Sunday after the full moon that occurs next after the vernal equinox, is not a precise statement of the actual ecclesiastical rules. The full moon involved is not the astronomical Full Moon but an ecclesiastical moon (determined from tables) that keeps, more or less, in step with the astronomical Moon.


The result is that Easter can never occur before March 22 or later than April 25. The Gregorian dates for the ecclesiastical full moon come from the Gregorian tables. 


Therefore, the civil date of Easter depends upon which tables - Gregorian or pre-Gregorian - are used. The western (Roman Catholic and Protestant) Christian churches use the Gregorian tables; many eastern (Orthodox) Christian churches use the older tables based on the Julian Calendar.


In a congress held in 1923, the eastern churches adopted a modified Gregorian Calendar and decided to set the date of Easter according to the astronomical Full Moon for the meridian of Jerusalem. However, a variety of practices remain among the eastern churches.


Inevitably, then, the date of Easter occasionally differs from a date that depends on the astronomical Full Moon and vernal equinox. In some cases this difference may occur in some parts of the world and not in others because two dates separated by the International Date Line are always simultaneously in progress on the Earth.


Source: U.S. Naval Observatory

 

 


 

Classifieds

Weekly specialty items listings, garage sales, and much more!

 

Current Ads

 

If you would like to place a Classified Ad, call Patrick at 510-614-1558.

Biz Spotlight

Tell us about your local business, events, and special offerings. Where you make the news!

 

Submission form

Real Estate

Get the latest in housing news and services delivered to you in full color PDF.

 

Browse this weeks gallery