In Western Christianity, Easter always falls on a Sunday from March 22 to April 25 inclusive. The following day, Easter Monday, is a legal holiday in many countries with predominantly Christian traditions.rnrnEaster and the holidays that are related to it are moveable feasts, in that they do not fall on a fixed date in the Gregorian or Julian calendars (which follow the motion of the sun and the seasons). Instead, they are based on a lunar calendar similarbut not identicalto the Hebrew Calendar. The precise date of Easter has often been a matter for contention.rnrnAt the First Council of Nicaea in 325 it was decided that Easter would be celebrated on the same Sunday throughout the Church, but it is probable that no method was specified by the Council. (No contemporary account of the Council's decisions has survived.) Instead, the matter seems to have been referred to the church of Alexandria, which city had the best reputation for scholarship at the time. The Catholic Epiphanius wrote in the mid-4th Century, "...the emperor...convened a council of 318 bishops...in the city of Nicea...They passed certain ecclesiastical canons at the council besides, and at the same time decreed in regard to the Passover 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..."(Epiphanius. The Panarion of Epiphanius of Salamis, Books II and III (Sects 47-80), De Fide). Section VI, Verses 1,1 and 1,3. Translated by Frank Williams. EJ Brill, New York, 1994, pp.471-472).rnrnThe practice of those following Rome was to celebrate Easter on the first Sunday after the earliest fourteenth day of a lunar month that occurred on or after March 21. During the Middle Ages this practice was more succinctly phrased as Easter is observed on the Sunday after the first full moon on or after the day of the vernal equinox. This full moon is called the Paschal full moon. The Church of Rome used its own methods to determine Easter until the 6th century, when it may have adopted the Alexandrian method as converted into the Julian calendar by Dionysius Exiguus (certain proof of this does not exist until the ninth century). Most churches in the British Isles used a late third century Roman method to determine Easter until they adopted the Alexandrian method at the Synod of Whitby in 664. 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 western churches now use the Gregorian calendar to calculate the date and Eastern Orthodox churches use the original Julian calendar, their dates are not usually aligned in the present day.rnrnAt a summit in Aleppo, Syria, in 1997, the World Council of Churches proposed a reform in the calculation of Easter which would have replaced an equation-based method of calculating Easter with direct astronomical observation; this would have side-stepped the calendar issue and eliminated the difference in date between the Eastern and Western churches. The reform was proposed for implementation starting in 2001, but it was not ultimately adopted by any member body.rnrnFurther information: Reform of the date of Easter rnA few clergymen of various denominations have advanced the notion of disregarding the moon altogether in determining the date of Easter; proposals include always observing the feast on the second Sunday in April, or always having seven Sundays between the Epiphany and Ash Wednesday, producing the same result except that in leap years Easter could fall on April 7. These suggestions have yet to attract significant support, and their adoption in the future is considered unlikely.rnrn[edit]rnComputationsrnThe calculations for the date of Easter are somewhat complicated. See computus for a discussion covering both the traditional tabular methods and more exclusively mathematical algorithms such as the one developed by mathematician Carl Friedrich Gauss.rnrnIn the Western Church, Easter has not fallen on the earliest of the 35 possible dates, March 22, since 1818, and will not do so again until 2285. It will, however, fall on March 23, just one day after its earliest possible date in 2008. Easter last fell on the latest possible date, April 25 in 1943, and will next fall on that date in 2038. However, it will fall on April 24, just one day before this latest possible date in 2011.rnrnHistorically, other forms of determining the holiday's date were also used. For example, Quartodecimanism was the practice of setting the holiday on the 14th day of the Jewish month of Nisan, which is the day of preparation for Passover.rnrn[edit]rnPosition in the church yearrn[edit]rnWestern ChristianityrnIn Western Christianity, Easter marks the end of the forty days of Lent, a period of fasting and penitence in preparation for Easter which begins on Ash Wednesday and ends at Easter Sunday.rnrnThe week before Easter is very special in the Christian tradition: the Sunday before is Palm Sunday, and the last three days before Easter are Maundy Thursday or Holy Thursday, Good Friday and Holy Saturday (sometimes referred to as Silent Saturday). Palm Sunday, Maundy Thursday and Good Friday respectively commemorate Jesus' entry in Jerusalem, the Last Supper and the Crucifixion. Holy Thursday, Good Friday, and Holy Saturday are sometimes referred to as the Easter Triduum (Latin for "Three Days"). In some countries, Easter lasts two days, with the second called "Easter Monday". The week beginning with Easter Sunday is called Easter Week or the Octave of Easter, and each day is prefaced with 'Easter', e.g. Easter Monday, Easter Tuesday, etc. Easter Saturday is therefore the Saturday after Easter Sunday. The day before Easter is properly called Holy Saturday. Many churches start celebrating Easter late in the evening of Holy Saturday at a service called the Easter Vigil.rnrnEastertide, the season of Easter, begins on Easter Sunday and lasts until the day of Pentecost, seven weeks later.rnrn[edit]rnEastern ChristianityrnIn Eastern Christianity, preparations begin with Great Lent. Following the fifth Sunday of Great Lent is Palm Week, which ends with Lazarus Saturday. Lazarus Saturday officially brings Great Lent to a close, although the fast continues for the following week. After Lazarus Saturday comes Palm Sunday, Holy Week, and finally Easter itself, or Pascha (Πάσχα), and the fast is broken immediately after the Divine Liturgy. Easter is immediately followed by Bright Week, during which there is no fasting, even on Wednesday and Friday.rnrnThe Paschal Service consists of Paschal Matins, Hours, and Liturgy, which traditionally begins at midnight of Pascha morning. Placing the Paschal Divine Liturgy at midnight guarantees that no Divine Liturgy will come earlier in the morning, ensuring its place as the pre-eminent "Feast of Feasts" in the liturgical year.rnrn[edit]rnReligious observation of Easterrn[edit]rnWestern ChristianityrnThe Easter festival is kept in many different ways among Western Christians. The traditional, liturgical observation of Easter, as practised among Roman Catholics and some Lutherans and Anglicans begins on the night of Holy Saturday with the Easter Vigil. This, the most important liturgy of the year, begins in total darkness with the blessing of the Easter fire, the lighting of the large Paschal candle (symbolic of the Risen Christ) and the chanting of the Exsultet or Easter Proclamation attributed to Saint Ambrose of Milan. After this service of light, a number of readings from the Old Testament are read; these tell the stories of creation, the sacrifice of Isaac, the crossing of the Red Sea, and the foretold coming of the Messiah. This part of the service climaxes with the singing of the Alleluia and the proclamation of the gospel of the resurrection. A sermon may be preached after the gospel. Then the focus moves from the lectern to the font. Anciently, Easter was considered the most perfect time to receive baptism, and this practice is alive in Roman Catholicism, as it is the time when new members are initiated into the Church, and it is being revived in some other circles. Whether there are baptisms at this point or not, it is traditional for the congregation to renew the vows of their baptismal faith. This act is often sealed by the sprinkling of the congregation with holy water from the font. The Catholic sacrament of Confirmation is also celebrated at the Vigil. The Easter Vigil concludes with the celebration of the Eucharist and Holy Communion. Additional celebrations are usually offered on Easter Sunday itself. Some churches prefer to keep this vigil very early on the Sunday morning instead of the Saturday night to reflect the gospel account of the women coming to the tomb at dawn on the first day of the week. Some churches read the Old Testament lessons before the procession of the Paschal candle, and then read the gospel immediately after the Exsultet.rnrnIn predominantly Roman Catholic Philippines, the morning of Easter (known in the national language as "Pasko ng Muling Pagkabuhay" or the Pasch of the Resurrection) is marked with joyous celebration, the first being the dawn "Salubong", wherein large statues of Jesus and Mary are brought together to meet, imagining the first reunion of Jesus and his mother Mary after Jesus' Resurrection. This is followed by the joyous Easter Mass.rnrnSome Christians wear their Sunday best to Church. This means a more formal dress and hats for some women.rnrn[edit]rnEastern ChristianityrnEaster is the fundamental and most important festival of the Eastern and Oriental Orthodox. Every other religious festival on their calendars, including Christmas, is at best secondary in importance to the celebration of the Resurrection of the Lord. This is reflected in the cultures of countries that are traditionally Orthodox Christian majority. Easter-connected social customs are native and rich. Christmas customs, on the other hand, are usually foreign imports, either from Germany or the USA. Eastern Rite Catholics in communion with the Pope of Rome have similar emphasis in their calendars, and many of their liturgical customs are very similar.rnrnThis is not to say that Christmas and other elements of the Christian liturgical calendar are ignored. Instead, these events are all seen as necessary but preliminary to the full climax of the Resurrection, in which all that has come before reaches fulfilment and fruition. Pascha (Easter) is the primary act that fulfils the purpose of Christ's ministry on earthto defeat death by dying and to purify and exalt humanity by voluntarily assuming and overcoming human frailty. This is succinctly summarized by the Paschal Troparion, sung repeatedly during Pascha until the Apodosis of Pascha (which is the day before Ascension):