Easter

== Date ==
{{Main|Date of Easter}}
Easter and the holidays that are related to it are [[moveable feast]]s, in that they do not fall on a fixed date in the [[Gregorian calendar|Gregorian]] or [[Julian calendar|Julian]] calendars (both of which follow the cycle of the sun and the seasons). Instead, the date for Easter is determined on a [[lunisolar calendar]] similar to the [[Hebrew calendar]]. The [[First Council of Nicaea]] (325) established two rules{{snd}} independence of the Jewish calendar and worldwide uniformity{{snd}} which were the only rules for Easter explicitly laid down by the council. No details for the computation were specified; these were worked out in practice, a process that took centuries and generated a number of [[Easter controversy|controversies]]. (See also [[Computus]] and [[Reform of the date of Easter]].) In particular, the Council did not decree that Easter must fall on Sunday, but this was already the practice almost everywhere.<ref>{{citation |author=Sozomen |author-link=Sozomen |title=The Ecclesiastical History of Sozomen |url=http://www.ccel.org/ccel/schaff/npnf202.iii.html |access-date=10 February 2023 |archive-date=10 February 2023 |archive-url=https://web.archive.org/web/20230210105751/https://www.ccel.org/ccel/schaff/npnf202.iii.html |url-status=live }} Book 7, Chapter 18</ref>

In Western Christianity, using the Gregorian calendar, Easter always falls on a Sunday between 22 March and 25 April,<ref>{{cite web|url=https://www.bbc.com/news/magazine-35880795|title=Why Can't the Date of Easter be Fixed|publisher=BBC |author=Caroline Wyatt|date=25 March 2016|access-date=13 April 2017|archive-date=24 November 2021|archive-url=https://web.archive.org/web/20211124001359/https://www.bbc.com/news/magazine-35880795|url-status=live}}</ref> within about seven days after the astronomical full moon.<ref>[http://aa.usno.navy.mil/faq/docs/easter.php The Date of Easter] {{Webarchive|url=https://web.archive.org/web/20110814045718/http://aa.usno.navy.mil/faq/docs/easter.php |date=14 August 2011 }}. Article from [[United States Naval Observatory]] (27 March 2007).</ref> The preceding Friday, [[Good Friday]], and following Monday, [[Easter Monday]], are [[legal holiday]]s in many countries with predominantly Christian traditions.<ref>{{Cite web|title=Easter Monday in Hungary in 2021|url=https://www.officeholidays.com/holidays/easter-monday|access-date=3 April 2021|website=Office Holidays |archive-date=5 November 2021|archive-url=https://web.archive.org/web/20211105114204/https://www.officeholidays.com/holidays/easter-monday|url-status=live}}</ref>

[[Eastern Orthodoxy|Eastern Orthodox]] Christians use the same rule but base their 21 March according to the Julian calendar. Because of the thirteen-day difference between the calendars from 1900 through 2099, 21 March Julian corresponds to 3 April in the Gregorian calendar (during the 20th and 21st centuries). Consequently, the date of Orthodox Easter varies between 4 April and 8 May in the Gregorian calendar. Orthodox Easter is usually several days or more than a month later than Western Easter.

Among the [[Oriental Orthodoxy|Oriental Orthodox]], some churches have changed from the Julian to the Gregorian calendar and the date for Easter, as for other fixed and moveable feasts, is the same as in the Western church.<ref>"The Church in Malankara switched entirely to the Gregorian calendar in 1953, following Encyclical No. 620 from Patriarch Mor Ignatius Aphrem I, dt. December 1952." [http://sor.cua.edu/Calendar/index.html Calendars of the Syriac Orthodox Church] {{Webarchive|url=https://web.archive.org/web/20100224054556/http://sor.cua.edu/Calendar/index.html |date=24 February 2010 }}. Retrieved 22 April 2009</ref>

=== Computations ===
In 725, [[Bede]] succinctly wrote, "The Sunday following the full Moon which falls on or after the [[equinox]] will give the lawful Easter."<ref>{{cite book|last=Wallis|first=Faith|title=Bede: The Reckoning of Time|date=1999|publisher=Liverpool University Press|isbn=0853236933|page=[https://books.google.com/books?id=yFsw-Vaup6sC&pg=PA148 148]|title-link=The Reckoning of Time}}</ref> However, this does not precisely reflect the ecclesiastical rules. The full moon referred to (called the [[Paschal full moon]]) is not an astronomical full moon, but the [[ecclesiastical full moon|14th day]] of a [[lunar month]]. Another difference is that the [[Equinox|astronomical equinox]] is a natural astronomical phenomenon, which can fall on 19, 20 or 21 March,<ref>[http://earthsky.org/astronomy-essentials/full-moon-vernal-equinox-date-of-easter Why is Easter so early this year?] {{Webarchive|url=https://web.archive.org/web/20210419030303/https://earthsky.org/astronomy-essentials/full-moon-vernal-equinox-date-of-easter |date=19 April 2021 }}, EarthSky, Bruce McClure in Astronomy Essentials, 30 March 2018.</ref> while the ecclesiastical date is fixed by convention on 21 March.<ref>Paragraph 7 of [[Inter gravissimas]] [http://isotc.iso.org/livelink/livelink/fetch/2000/2122/138351/138352/1311683/4020763/2015225/8601RevN005_Inter_Gravissimas.pdf?nodeid=2179035&vernum=0refers ISO.org] {{Webarchive|url=https://web.archive.org/web/20220714160228/https://login.iso.org/idp/SSO.saml2?SAMLRequest=fVLLbsIwEPyVyPe8HMTDIpFSOBSJloikPfSCTLKAVWOnXoe2f98k0EIvXFaWdnZmdrxT5EdZs7SxB7WGjwbQOl9HqZD1jZg0RjHNUSBT%2FAjIbMny9GnJqBew2mirSy2JkyKCsUKrmVbYHMHkYE6ihJf1MiYHa2tkvi9Q29Jrq6fN3pfiBFKo9%2BsjP4jtVkuwBw9R%2B50M9bNVXhBn3voSincKVz6p90L98Ymq9vN85XW%2BKXEW85hsgircReMxn0xgwMOKB5wOYAhRWUbDakijFobYwEKh5crGhAaUusHIDQdFOGQBZXT0RpzssuaDUJVQ%2B%2FuZbM8gZI9Fkbln969gsHfeAkgy7RyyXtjcZH2flv8GTJIOdlma8bqWouxzcSvYdT9Sbdrmps966t9InXVr9txyL%2BaZbue%2BnVRK%2FTkzwC3EJCR%2Bch75fxDJDw%3D%3D&RelayState=https%3A%2F%2Fisotc.iso.org%2Flivelink%2Flivelink%2Ffetch%2F2000%2F2122%2F138351%2F138352%2F1311683%2F4020763%2F2015225%2F8601RevN005_Inter_Gravissimas.pdf%3Fnodeid%3D2179035%26vernum%3D0refers&SigAlg=http%3A%2F%2Fwww.w3.org%2F2000%2F09%2Fxmldsig%23rsa-sha1&Signature=frB%2BJ%2FurXZDghPJm9huiZCq14gY2WIeGWOFOoWlNxfvWrDpaTEOudKYAui7nbgBTBkZArsQGvs5AgK4U1au3iifHt83yClQ5j4VHpDHqXJjilPM%2FzL6hgwl1uwU1hoykZ1V8URkAUazJRUvJlSaboeRRYQtIm1bDLAZLF%2BS3t58%3D |date=14 July 2022 }} to "the vernal equinox, which was fixed by the fathers of the [first] [[First Council of Nicaea|Nicene Council]] at XII calends April [21 March]". This definition can be traced at least back to chapters 6 & 59 of [[Bede]]'s ''[[De temporum ratione]]'' (725).</ref>

In addition, the lunar tables of the Julian calendar are currently five days behind those of the Gregorian calendar. Therefore, the Julian computation of the Paschal full moon is a full five days later than the astronomical full moon. The result of this combination of solar and lunar discrepancies is divergence in the date of Easter in most years (see table).<ref name="dateACC">{{cite web |title=Date of Easter |url=https://www.anglican.ca/ask/faq/easter/ |website=The Anglican Church of Canada |access-date=5 April 2021 |archive-date=26 December 2021 |archive-url=https://web.archive.org/web/20211226225037/https://www.anglican.ca/ask/faq/easter/ |url-status=live }}</ref>

Easter is determined on the basis of [[lunisolar calendar|lunisolar]] cycles. The lunar year consists of 30-day and 29-day lunar months, generally alternating, with an [[embolismic month]] added periodically to bring the lunar cycle into line with the solar cycle. In each solar year (1 January to 31 December inclusive), the lunar month beginning with an [[ecclesiastical new moon]] falling in the 29-day period from 8 March to 5 April inclusive is designated as the paschal lunar month for that year.<ref name="smart.net">Montes, Marcos J. [http://www.smart.net/~mmontes/ec-cal.html "Calculation of the Ecclesiastical Calendar"] {{webarchive |url=https://web.archive.org/web/20081103111329/http://www.smart.net/~mmontes/ec-cal.html |date=3 November 2008 }}. Retrieved 12 January 2008.</ref>

Easter is the third Sunday in the paschal lunar month, or, in other words, the Sunday after the paschal lunar month's 14th day. The 14th of the paschal lunar month is designated by convention as the [[Paschal full moon]], although the 14th of the lunar month may differ from the date of the astronomical full moon by up to two days.<ref name="smart.net"/> Since the ecclesiastical new moon falls on a date from 8 March to 5 April inclusive, the paschal full moon (the 14th of that lunar month) must fall on a date from 22 March to 18 April inclusive.<ref name="dateACC"/>

The Gregorian calculation of Easter was based on a method devised by the [[Calabria]]n doctor [[Aloysius Lilius]] (or Lilio) for adjusting the [[epact]]s of the Moon,<ref>G Moyer (1983), [http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?journal=grc..&year=1983&volume=book&page_ind=181 "Aloisius Lilius and the 'Compendium novae rationis restituendi kalendarium'"] {{Webarchive|url=https://web.archive.org/web/20211012082725/http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?journal=grc..&year=1983&volume=book&page_ind=181 |date=12 October 2021 }}, pp. 171–188 in G.V. Coyne (ed.).</ref> and has been adopted by almost all Western Christians and by Western countries which celebrate national holidays at Easter. For the British Empire and colonies, a determination of the date of Easter Sunday using [[Golden number (time)|Golden Numbers]] and [[Dominical letter|Sunday letters]] was defined by the [[Calendar (New Style) Act 1750]] with its Annexe. This was designed to match exactly the Gregorian calculation.<ref name="legislation.gov.uk-calendar">{{cite web |title=Calendar (New Style) Act 1750 |url=https://www.legislation.gov.uk/apgb/Geo2/24/23 |website=legislation.gov.uk|access-date=23 April 2023|archive-date=April 23, 2023 |archive-url=https://web.archive.org/web/20230423123410/https://www.legislation.gov.uk/apgb/Geo2/24/23 |url-status=live }}</ref>

=== Controversies over the date ===
{{Main|Easter controversy}}
[[File:5part-icon.jpeg|thumb|A five-part [[Russian Orthodox]] icon depicting the Easter story. [[Eastern Orthodoxy|Eastern Orthodox]] Christians use a different computation for the date of Easter from the Western churches.]]

The precise date of Easter has at times been a matter of contention. By the later 2nd century, it was widely accepted that the celebration of the holiday was a practice of the [[Disciple (Christianity)|disciples]] and an undisputed tradition. The [[Quartodecimanism|Quartodeciman]] controversy, the first of several [[Easter controversy|Easter controversies]], arose concerning the date on which the holiday should be celebrated.<ref name="NEW ADVENT 1909">{{cite encyclopedia |last=Thurston|first=Herbert| title=Easter Controversy | encyclopedia =The Catholic Encyclopedia | date=1909-05-01 | url=http://www.newadvent.org/cathen/05228a.htm |archive-url=https://web.archive.org/web/20230423124325/https://www.newadvent.org/cathen/05228a.htm|archive-date=April 23, 2023| access-date=2023-04-23 |publisher=New York: Robert Appleton Company|volume=5|via=New Advent}}</ref>

The term "Quartodeciman" refers to the practice of ending the Lenten fast on [[Nisan]] 14 of the [[Hebrew calendar]], "the {{LORD}}'s passover".<ref>{{bibleverse|Leviticus|23:5|ESV}}</ref> According to the church historian [[Eusebius of Caesarea|Eusebius]], the Quartodeciman [[Polycarp]] (bishop of [[Smyrna]], by tradition a disciple of [[John the Apostle]]) debated the question with [[Pope Anicetus|Anicetus]] (bishop of Rome). The [[Asia (Roman province)|Roman province of Asia]] was Quartodeciman, while the Roman and Alexandrian churches continued the fast until the Sunday following (the Sunday of Unleavened Bread), wishing to associate Easter with Sunday. Neither Polycarp nor Anicetus persuaded the other, but they did not consider the matter [[schism (religion)|schismatic]] either, parting in peace and leaving the question unsettled.<ref name="Christian Classics Ethereal Library 2">{{cite web |first1=Philip|last1=Schaff|first2=Tim|last2=Perrine|title= NPNF2-01. Eusebius Pamphilius: Church History, Life of Constantine, Oration in Praise of Constantine|via= Christian Classics Ethereal Library| url=https://ccel.org/ccel/schaff/npnf201/npnf201.ii.html | access-date=2023-04-23|series=Nicene and Post-Nicene Fathers|url-status=live|archive-url=https://web.archive.org/web/20220730023344/https://ccel.org/ccel/schaff/npnf201/npnf201.i.html|archive-date=July 30, 2022}}</ref>

Controversy arose when [[Pope Victor I|Victor]], bishop of Rome a generation after Anicetus, attempted to [[excommunication|excommunicate]] [[Polycrates of Ephesus]] and all other bishops of Asia for their Quartodecimanism. According to Eusebius, a number of synods were convened to deal with the controversy, which he regarded as all ruling in support of Easter on Sunday.<ref>Eusebius, Church History 5.23.</ref> Polycrates ({{circa|190}}), however, wrote to Victor defending the antiquity of Asian Quartodecimanism. Victor's attempted excommunication was apparently rescinded, and the two sides reconciled upon the intervention of bishop [[Irenaeus]] and others, who reminded Victor of the tolerant precedent of Anicetus.<ref name="Kelly 1978 p. ">{{cite book | last=Kelly | first=J. N. D. | title=Early Christian doctrines | publication-place=San Francisco | date=1978 | isbn=0-06-064334-X | oclc=3753468 | publisher=Harper & Row | page=}}</ref><ref name="Grace Communion International 2018">{{cite web | title=The Passover-Easter-Quartodeciman Controversy | website=Grace Communion International | date=2018-11-22 | url=https://www.gci.org/articles/the-passover-easter-quartodeciman-controversy/ | access-date=2023-04-23}}</ref>

Quartodecimanism seems to have lingered into the 4th century, when [[Socrates of Constantinople]] recorded that some Quartodecimans were deprived of their churches by [[John Chrysostom]]<ref>Socrates, ''Church History'', 6.11, at {{cite web| last = Schaff| first = Philip| title = Of Severian and Antiochus: their Disagreement from John.| work = Socrates and Sozomenus Ecclesiastical Histories| publisher = Calvin College Christian Classics Ethereal Library| date = 13 July 2005| url = http://www.ccel.org/ccel/schaff/npnf202.ii.ix.xii.html| access-date = 28 March 2009| archive-date = 13 October 2010| archive-url = https://web.archive.org/web/20101013152952/http://www.ccel.org/ccel/schaff/npnf202.ii.ix.xii.html| url-status = live}}</ref> and that some were harassed by [[Nestorius]].<ref>Socrates, ''Church History'' 7.29, at {{cite web| last = Schaff| first = Philip| title = Nestorius of Antioch promoted to the See of Constantinople. His Persecution of the Heretics.| work = Socrates and Sozomenus Ecclesiastical Histories| publisher = Calvin College Christian Classics Ethereal Library| date = 13 July 2005| url = http://www.ccel.org/ccel/schaff/npnf202.ii.x.xxix.html| access-date = 28 March 2009| archive-date = 13 October 2010| archive-url = https://web.archive.org/web/20101013184700/http://www.ccel.org/ccel/schaff/npnf202.ii.x.xxix.html| url-status = live}}</ref>

It is not known how long the Nisan 14 practice continued. But both those who followed the Nisan 14 custom, and those who set Easter to the following Sunday, had in common the custom of consulting their Jewish neighbors to learn when the month of Nisan would fall, and setting their festival accordingly. By the later 3rd century, however, some Christians began to express dissatisfaction with the custom of relying on the Jewish community to determine the date of Easter. The chief complaint was that the Jewish communities sometimes erred in setting Passover to fall before the [[Northern Hemisphere]] spring equinox.<ref>Eusebius, ''Church History'', 7.32.</ref><ref>Peter of Alexandria, quoted in the [[Chronicon Paschale]]. In Alexander Roberts and James Donaldson, eds., ''Ante-Nicene Christian Library, Volume 14: The Writings of Methodius, Alexander of Lycopolis, Peter of Alexandria, And Several Fragments'', Edinburgh, 1869, p. 326, at {{cite web| last = Donaldson| first = Alexander| title = That Up to the Time of the Destruction of Jerusalem, the Jews Rightly Appointed the Fourteenth Day of the First Lunar Month.| work = Gregory Thaumaturgus, Dionysius the Great, Julius Africanus, Anatolius and Minor Writers, Methodius, Arnobius| publisher = Calvin College Christian Classics Ethereal Library| date = 1 June 2005| url = http://www.ccel.org/ccel/schaff/anf06.ix.vi.v.html| access-date = 28 March 2009| archive-date = 15 April 2009| archive-url = https://web.archive.org/web/20090415004506/http://www.ccel.org/ccel/schaff/anf06.ix.vi.v.html| url-status = live}}</ref> The [[Sardica paschal table]]<ref>MS Verona, Biblioteca Capitolare LX(58) folios 79v–80v.</ref> confirms these complaints, for it indicates that the Jews of some eastern Mediterranean city (possibly [[Antioch]]) fixed Nisan 14 on dates well before the spring equinox on multiple occasions.<ref>Sacha Stern, ''Calendar and Community: A History of the Jewish Calendar Second Century BCE – Tenth Century CE,'' Oxford, 2001, pp. 124–132.</ref>

Because of this dissatisfaction with reliance on the Jewish calendar, some Christians began to experiment with independent computations.{{refn|Eusebius reports that Dionysius, Bishop of Alexandria, proposed an 8-year Easter cycle, and quotes a letter from Anatolius, Bishop of Laodicea, that refers to a 19-year cycle.<ref>Eusebius, ''Church History'', 7.20, 7.31.</ref> An 8-year cycle has been found inscribed on a statue unearthed in Rome in the 17th century, and since dated to the 3rd century.<ref>Allen Brent, ''Hippolytus and the Roman Church in the Third Century'', Leiden: E.J. Brill, 1995.</ref>|group=nb}} Others, however, believed that the customary practice of consulting Jews should continue, even if the Jewish computations were in error.<ref name="NEW ADVENT (Church Fathers)">{{cite encyclopedia| title=Church History, Book II (Eusebius) |series=Nicene and Post-Nicene Fathers, second series|volume=1|publisher=Christian Literature Publishing Co.|date=January 1, 1890|url=https://www.newadvent.org/fathers/250102.htm | via=New Advent|translator=Arthur Cushman McGiffert| access-date=2023-04-23|editor1=Philip Schaff|editor2=Henry Wace}}</ref>

=== First Council of Nicaea (325 AD) ===
{{main|First Council of Nicaea}}

This controversy between those who advocated independent computations, and those who wished to continue the custom of relying on the Jewish calendar, was formally resolved by the [[First Council of Nicaea]] in 325, which endorsed changing to an independent computation by the Christian community in order to celebrate in common. This effectively required the abandonment of the old custom of consulting the Jewish community in those places where it was still used. [[Epiphanius of Salamis]] wrote in the mid-4th century:

{{blockquote|[T]he [[Constantine I|emperor]]{{nbsp}}[...] convened a council of 318 bishops{{nbsp}}[...] in the city of Nicaea{{nbsp}}[...] They passed certain ecclesiastical canons at the council besides, and at the same time decreed in regard to the Passover [i.e., Easter] that there must be one unanimous concord on the celebration of God's holy and supremely excellent day. For it was variously observed by people; some kept it early, some between [the disputed dates], but others late. And in a word, there was a great deal of controversy at that time.<ref name = Epiphianus>Epiphanius, ''Adversus Haereses'', Heresy 69, 11,1, in {{cite book | last = Willams | first = F. | title = The Panarion of Epiphianus of Salamis Books II and III | publisher = E.J. Brill |date=1994 | location = Leiden | page = 331}}</ref>}}

Canons<ref>Apostolic Canon 7: "If any bishop, presbyter, or deacon shall celebrate the holy day of Easter before the vernal equinox with the Jews, let him be deposed." ''A Select Library of Nicene and Post-Nicene Fathers of the Christian Church,'' Second Series, Volume 14: The Seven Ecumenical Councils, Eerdmans, 1956, p. 594.</ref> and sermons<ref>St. John Chrysostom, "Against those who keep the first Passover", in ''Saint John Chrysostom: Discourses against Judaizing Christians'', translated by Paul W. Harkins, Washington, DC, 1979, pp. 47ff.</ref> condemning the custom of computing Easter's date based on the Jewish calendar indicate that this custom (called "protopaschite" by historians) did not die out at once, but persisted for a time after the Council of Nicaea.<ref name="McGuckin 2011 p.223 ">{{cite book | last=McGuckin | first=John Anthony | title=The encyclopedia of Eastern Orthodox Christianity | publisher=Wiley-Blackwell | publication-place=Maldin, MA | date=2011 | isbn=978-1-4443-9253-1 | oclc=703879220 | page=223}}</ref>

[[Dionysius Exiguus]], and others following him, maintained that the 318 bishops assembled at Nicaea had specified a particular method of determining the date of Easter; subsequent scholarship has refuted this tradition.<ref>{{cite book|last=Mosshammer|first=Alden A.|title=The Easter Computus and the Origins of the Christian Era|date=2008|publisher=Oxford University Press|location=Oxford|isbn=978-0-19-954312-0|pages=50–52, 62–65}}</ref> In any case, in the years following the council, the computational system that was worked out by the church of Alexandria came to be normative. The Alexandrian system, however, was not immediately adopted throughout Christian Europe. Following [[Augustalis (bishop)|Augustalis]]' treatise {{lang|la|De ratione Paschae}} (On the Measurement of Easter), Rome retired the earlier [[octaeteris|8-year cycle]] in favor of Augustalis' 84-year [[lunisolar calendar]] cycle, which it used until 457. It then switched to [[Victorius of Aquitaine]]'s adaptation of the Alexandrian system.<ref name="Mosshammer 2008 239–244">{{cite book|last=Mosshammer|first=Alden A.|title=The Easter Computus and the Origins of the Christian Era|date=2008|publisher=Oxford University Press|location=Oxford|isbn=978-0-19-954312-0|pages=239–244}}</ref><ref name="Holford-Strevens, Leofranc 1999 808–809">{{cite book|last1=Holford-Strevens |first1=Leofranc |last2= Blackburn |first2= Bonnie |title=The Oxford Companion to the Year|date=1999|publisher=Oxford University Press|location=Oxford|isbn=0-19-214231-3|pages=[https://archive.org/details/oxfordcompaniont00blac/page/808 808–809]|url=https://archive.org/details/oxfordcompaniont00blac/page/808}}</ref>

Because this Victorian cycle differed from the unmodified Alexandrian cycle in the dates of some of the Paschal full moons, and because it tried to respect the Roman custom of fixing Easter to the Sunday in the week of the 16th to the 22nd of the lunar month (rather than the 15th to the 21st as at Alexandria), by providing alternative "Latin" and "Greek" dates in some years, occasional differences in the date of Easter as fixed by Alexandrian rules continued.<ref name="Mosshammer 2008 239–244"/><ref name="Holford-Strevens, Leofranc 1999 808–809"/> The Alexandrian rules were adopted in the West following the tables of Dionysius Exiguus in 525.<ref name="Declercq 2000 p.143-144">{{cite book | last=Declercq | first=Georges | title=Anno Domini : the origins of the Christian era | publisher=Turnhout |location= Belgium | date=2000 | isbn=2-503-51050-7 | oclc=45243083 | pages=143–144}}</ref>

Early Christians in Britain and Ireland also used an 84-year cycle. From the 5th century onward this cycle set its equinox to 25 March and fixed Easter to the Sunday falling in the 14th to the 20th of the lunar month inclusive.<ref>{{cite book|last=Mosshammer|first=Alden A.|title=The Easter Computus and the Origins of the Christian Era|date=2008|publisher=Oxford University Press|location=Oxford|isbn=978-0-19-954312-0|pages=223–224}}</ref><ref>{{cite book|last=Holford-Strevens |first1=Leofranc |last2= Blackburn |first2= Bonnie|title=The Oxford Companion to the Year|date=1999|publisher=Oxford University Press|location=Oxford|isbn=0-19-214231-3|pages=[https://archive.org/details/oxfordcompaniont00blac/page/870 870–875]|url=https://archive.org/details/oxfordcompaniont00blac/page/870}}</ref> This 84-year cycle was replaced by the Alexandrian method in the course of the 7th and 8th centuries. Churches in western continental Europe used a late Roman method until the late 8th century during the reign of [[Charlemagne]], when they finally adopted the Alexandrian method. Since 1582, when the [[Roman Catholic Church]] adopted the Gregorian calendar while most of Europe used the Julian calendar, the date on which Easter is celebrated has again differed.<ref>{{cite web |title=Orthodox Easter: Why are there two Easters? |url=https://www.bbc.co.uk/newsround/48067272 |publisher=BBC Newsround |date=20 April 2020 |access-date=4 April 2021 |archive-date=23 December 2021 |archive-url=https://web.archive.org/web/20211223235240/https://www.bbc.co.uk/newsround/48067272 |url-status=live }}</ref>

The Greek island of [[Syros]], whose population is divided almost equally between Catholics and Orthodox, is one of the few places where the two Churches share a common date for Easter, with the Catholics accepting the Orthodox date—a practice helping considerably in maintaining good relations between the two communities.<ref>{{cite news | title=Easter: A date with God | url=http://www.economist.com/node/18584376 | date=20 April 2011 | newspaper=The Economist | access-date=23 April 2011 | quote=Only in a handful of places do Easter celebrants alter their own arrangements to take account of their neighbours. Finland's Orthodox Christians mark Easter on the Western date. And on the Greek island of Syros, a Papist stronghold, Catholics and Orthodox alike march to Orthodox time. The spectacular public commemorations, involving flower-strewn funeral biers on Good Friday and fireworks on Saturday night, bring the islanders together, rather than highlighting division. | archive-date=23 April 2018 | archive-url=https://web.archive.org/web/20180423192921/https://www.economist.com/node/18584376 | url-status=live }}</ref> Conversely, Orthodox Christians in Finland celebrate Easter according to the [[Western Christian]] date.<ref>{{cite news | title=Easter: A date with God | url=http://www.economist.com/node/18584376 | date=20 April 2011 | newspaper=The Economist | access-date=23 April 2011 | quote=Finland's Orthodox Christians mark Easter on the Western date. | archive-date=23 April 2018 | archive-url=https://web.archive.org/web/20180423192921/https://www.economist.com/node/18584376 | url-status=live }}</ref>

=== Proposed reforms of the date ===
{{See also|Reform of the date of Easter}}

In the 20th and 21st centuries, some individuals and institutions have propounded changing the method of calculating the date for Easter, the most prominent proposal being the Sunday after the second Saturday in April. Despite having some support, proposals to reform the date have not been implemented.<ref name=Britannica>{{cite encyclopedia | url=https://www.britannica.com/EBchecked/topic/176858/Easter | title=Easter (holiday) | publisher=Encyclopædia Britannica | encyclopedia=Encyclopædia Britannica Online | access-date=9 March 2013 | archive-date=3 May 2015 | archive-url=https://web.archive.org/web/20150503123607/http://www.britannica.com/EBchecked/topic/176858/Easter | url-status=live }}</ref> An Orthodox congress of Eastern Orthodox bishops, which included representatives mostly from the [[Ecumenical Patriarch of Constantinople|Patriarch of Constantinople]] and the [[Serbian Patriarch]], met in [[Constantinople]] in 1923, where the bishops agreed to the [[Revised Julian calendar]].<ref name="Hieromonk Cassian 1998, p.51">Hieromonk Cassian, ''A Scientific Examination of the Orthodox Church Calendar'', Center for Traditionalist Orthodox Studies, 1998, pp. 51–52, {{ISBN|0-911165-31-2}}.</ref>

The original form of this calendar would have determined Easter using precise astronomical calculations based on the meridian of [[Jerusalem in Christianity|Jerusalem]].<ref>M. Milankovitch, "Das Ende des julianischen Kalenders und der neue Kalender der orientalischen Kirchen", ''Astronomische Nachrichten'' 200, 379–384 (1924).</ref><ref>Miriam Nancy Shields, "[http://adsabs.harvard.edu/abs/1924PA.....32..407S The new calendar of the Eastern churches] {{Webarchive|url=https://web.archive.org/web/20150324181450/http://adsabs.harvard.edu/abs/1924PA.....32..407S |date=24 March 2015 }}", ''Popular Astronomy'' '''32''' (1924) 407–411 ([http://adsabs.harvard.edu/abs/1924PA.....32R.411H page 411] {{Webarchive|url=https://web.archive.org/web/20160112122020/http://adsabs.harvard.edu/abs/1924PA.....32R.411H |date=12 January 2016 }}). This is a translation of M. Milankovitch, "The end of the Julian calendar and the new calendar of the Eastern churches", ''Astronomische Nachrichten'' No. 5279 (1924).</ref> However, all the Eastern Orthodox countries that subsequently adopted the Revised Julian calendar adopted only that part of the revised calendar that applied to festivals falling on fixed dates in the Julian calendar. The revised Easter computation that had been part of the original 1923 agreement was never permanently implemented in any Orthodox diocese.<ref name="Hieromonk Cassian 1998, p.51"/>

In the [[United Kingdom]], [[Parliament of the United Kingdom|Parliament]] passed the [[Easter Act 1928]] to change the date of Easter to be the first Sunday after the second Saturday in April (or, in other words, the Sunday in the period from 9 to 15 April). However, the legislation has not been implemented, although it remains on the Statute book and could be implemented, subject to approval by the various Christian churches.<ref>{{cite web |url=https://publications.parliament.uk/pa/ld200405/ldhansrd/vo050406/text/50406w05.htm#wa_subhd_30 |title=Hansard Reports, April 2005, regarding the Easter Act of 1928 |publisher=United Kingdom Parliament |access-date=14 March 2010 |archive-date=8 June 2021 |archive-url=https://web.archive.org/web/20210608213713/https://publications.parliament.uk/pa/ld200405/ldhansrd/vo050406/text/50406w05.htm#wa_subhd_30 |url-status=live }}</ref>

At a summit in [[Aleppo]], Syria, in 1997, the [[World Council of Churches]] (WCC) proposed a [[Aleppo Easter dating method|reform in the calculation of Easter]] which would have replaced the present divergent practices of calculating Easter with modern scientific knowledge taking into account actual astronomical instances of the spring equinox and full moon based on the meridian of Jerusalem, while also following the tradition of Easter being on the Sunday following the full moon.<ref>[http://www.oikoumene.org/index.php?id=2677 WCC: Towards a common date for Easter] {{webarchive |url=https://web.archive.org/web/20071213064102/http://www.oikoumene.org/index.php?id=2677 |date=13 December 2007 }}</ref> The recommended World Council of Churches changes would have sidestepped the calendar issues and eliminated the difference in date between the Eastern and Western churches. The reform was proposed for implementation starting in 2001, and despite repeated calls for reform, it was not ultimately adopted by any member body.<ref>{{cite web |title=Why is Orthodox Easter on a different day? |url=https://uscatholic.org/articles/201504/why-do-catholics-and-orthodox-christians-celebrate-easter-on-different-days/ |publisher=U.S. Catholic magazine |date=3 April 2015 |access-date=5 April 2021 |archive-date=9 May 2021 |archive-url=https://web.archive.org/web/20210509040946/https://uscatholic.org/articles/201504/why-do-catholics-and-orthodox-christians-celebrate-easter-on-different-days/ |url-status=live }}</ref><ref>{{cite news |last=Iati |first=Marisa |title=Why Isn't Easter Celebrated on the Same Date Every Year? |url=https://www.washingtonpost.com/history/2019/04/20/why-isnt-easter-celebrated-same-date-every-year/ |newspaper=Washington Post |date=20 April 2019 |access-date=5 April 2021 |archive-date=10 December 2020 |archive-url=https://web.archive.org/web/20201210230738/https://www.washingtonpost.com/history/2019/04/20/why-isnt-easter-celebrated-same-date-every-year/ |url-status=live }}</ref>

In January 2016, the [[Anglican Communion]], [[Coptic Orthodox Church]], [[Greek Orthodox Church]], and Roman Catholic Church again considered agreeing on a common, universal date for Easter, while also simplifying the calculation of that date, with either the second or third Sunday in April being popular choices.<ref>[http://cathnews.com/cathnews/23940-christian-churches-close-to-deal-to-fix-common-date-for-easter "Christian Churches to Fix Common Date for Easter"] {{Webarchive|url=https://web.archive.org/web/20210609102939/https://cathnews.com/cathnews/23940-christian-churches-close-to-deal-to-fix-common-date-for-easter |date=9 June 2021 }} (18 January 2016).  ''CathNews.com''.  Retrieved 18 September 2018.</ref>

In November 2022, the Patriarch of Constantinople said that conversations between the Roman Catholic Church and the Orthodox Churches had begun to determine a common date for the celebration of Easter. The agreement is expected to be reached for the 1700th anniversary of the Council of Nicaea in 2025.<ref>{{Cite web |last=Hertz |first=Joachin Meisner |date=16 November 2022 |title=Patriarch of Constantinople: Conversations Are Underway for Catholics and Orthodox to Celebrate Easter on the Same Date |url=https://zenit.org/2022/11/16/patriarch-of-constantinople-conversations-are-underway-for-catholics-and-orthodox-to-celebrate-easter-on-the-same-date/ |access-date=18 November 2022 |website=ZENIT – English |archive-date=17 November 2022 |archive-url=https://web.archive.org/web/20221117185458/https://zenit.org/2022/11/16/patriarch-of-constantinople-conversations-are-underway-for-catholics-and-orthodox-to-celebrate-easter-on-the-same-date/ |url-status=live }}</ref>

=== Table of the dates of Easter by Gregorian and Julian calendars ===
{{see also|List of dates for Easter}}
The [[World Council of Churches|WCC]] presented comparative data of the relationships:
{{Table of dates of Easter|format=dmy}}