Difference between revisions of "Paschalion"

From OrthodoxWiki
Jump to: navigation, search
m (link)
m (with love from ebaums)
Line 1: Line 1:
[[Image:Pascha.jpg|right|Great and Holy Pascha]]
The '''Paschalion''' of the [[Orthodox Church]] combines the metonic and solar calendrical cycles to determine the date of [[Pascha]] for a given year.  A common formula to determine the date of Pascha was created in connection with the [[First Ecumenical Council]], held at [[Nicaea]] in 325 A.D.
== The Nicene Formula ==
Because of the inaccuracy of the [[Julian Calendar]], Pascha is drifting later into the year for those who use the Julian Paschalion.  Thus, while according to the calendar, for those using the Julian Calendar Pascha will always be sometime in March or April, it will eventually be celebrated in the northern hemisphere in the summer, the autumn, and then the winter.  For those using the [[Revised Julian Calendar]], the calendar date of Pascha is drifting along with its astronomical position.  The [[Gregorian Calendar]], which includes its own revised Paschalion, has neither of these problems.
== The Gregorian Reform ==
In October 1582, the [[Roman Catholic Church]] adopted a major calendar reform designed to correct for the 10-day drift in the vernal equinox since the First Ecumenical Council.  The Julian calendar then in common use was based on an average year of 365.25 days, slightly longer than the actual solar mean year of 365.24219 days. 
The new calendar was called the [[Gregorian Calendar|Gregorian]] after its sponsor, Pope Gregory XIII.  The reform also introduced refinements to the calculation of Pascha.
== East and West Today ==
The Roman Catholic and Protestant West eventually adopted the Gregorian Calendar for civil and ecclesiastical purposes, including the determination of Pascha.  The Orthodox East, however, was not so quick to change.  Even when the traditionally Orthodox countries began to adopt the Gregorian Calendar for civil purposes, the Orthodox Church retained the [[Julian Calendar]] and original Paschalion.  For the sake of convenience, the date of Pascha is often transposed to the coincident date on the Gregorian Calendar for reference. 
== Algorithms ==
''N.B. -- In this formula MOD is the modulus function, in which the first number is divided by the second and only the remainder is returned.  Further, all division is integer division, in which remainders are discarded.  Thus'' <tt>'''22 MOD 7 = 1'''</tt> ''but'' <tt>'''22 / 7 = 3'''.
G = ''year'' MOD 19
J = (''year'' + (''year''/4) + I) MOD 7
L = I - J
== Online Paschalion Utility ==
You can find the date of Pascha and many Pascha-dependent dates (e.g., the start of Great Lent, Pentecost, etc.) through this online JavaScript [http://www.noeticspace.com/paschalion Paschalion utility] (works best with IE3 or Netscape 3 or above).
A perpetual Paschalion utility is available [http://cgi.duke.edu/~aa63/cgi-bin/paschallion.cgi here]. The utility was created by [http://www.duke.edu/~aa63/ Aleksandr Andreev] of [http://www.duke.edu/ Duke University] and calculates Pascha and associated feasts for any series of years. It also calculates the numbers used in Paschal calculations which can be found in an Orthodox [[Typicon]].
==See also==
*[[Church Calendar]]
*[[Gaussian Formulae]]
== External links ==
*[http://www.oca.org/Docs.asp?ID=133&SID=12 Concerning the Date of Pascha and the 1st Ecumenical Council], by Archbishop [[Peter (L'Huillier) of New York]]
*[http://www.chrysostom.org/andrew/texts/parsells-calendar.pdf The Calendar Issue in the Orthodox Church], by John Parsells (PDF)
*[http://www.tondering.dk/claus/calendar.html Frequently Asked Questions about Calendars] by Claus Tondering (everything you ever wanted to know)
*[http://users.chariot.net.au/~gmarts/calmain.htm Calendar and Easter Topics]
[[Category:Church Life]]
[[Category:Featured Articles]]

Revision as of 11:30, June 10, 2008