In both the East and the West, the dates of many feasts vary from year to year, though in almost all cases this is due to the variation in the date of Passover, and all other dates follow from that. The extent to which the feasts and festivals are celebrated also varies between churches; in general Protestant churches observe far fewer of them than Catholic and Orthodox churches, and in particular are less likely to celebrate feasts of the Virgin Mary and the Saints. See moveable feasts.
The liturgical cycle divides the year into a series of seasons, each with their own mood, theological emphases, and modes of prayer, which can be signified by different ways of decorating churches, colors of Paraments and Vestments for clergy, scriptural readings, themes for preaching and even different traditions and practices often observed personally or in the home. In churches that follow the liturgical year, the scripture passages for each Sunday (and even each day of the year in some traditions) are specified by a list called a lectionary.
Among non-Catholic Western Christians, Anglicans and Lutherans have traditionally followed the lectionary since the days of the Protestant Reformation. Following the Roman Catholic liturgical reform of the Roman Rite instituted by Pope Paul VI in 1970, the adoption and use of lectionaries in other Protestant churches (Methodist, Reformed, United, etc.) increased. In particular, the growing influence of the Revised Common Lectionary led to a greater awareness of the Christian year among Protestants in the later decades of the 20th century, especially among mainline denominations.
Biblical calendars are based on the cycle of the new moon. The year is from the first new moon on or after the spring equinox to the next new moon on or after the spring equinox, which means it has no set starting point like the modern calendar. The basic formula for the calendar is found early in the Bible: "And God said, Let there be lights in the firmament of the heaven to divide the day from the night; and let them be for signs, and for seasons, and for days, and years" (Gen. 1:14). "This month shall be unto you the beginning of months: it shall be the first month of the year to you" (Exo. 12:1-2). "This day came ye out in the month Abib" (Exo. 13:4). A month is one new moon to the next new moon. "And it shall come to pass, that from one new moon to another (month), and from one Sabbath to another, shall all flesh come to worship before me, said the LORD" (Isa. 66:23). "In the first month, that is, the month Nisan, in the twelfth year of king Ahasuerus, they cast Pur, that is, the lot, before Haman from day to day, and from month to month, to the twelfth month, that is, the month Adar" (Est. 3:7). The Biblical Calendar is laid out as follows, Nisan or Nissan (1st month) March-April, Iyar (2nd month) April-May, Sivan (3rd month) May-June, Tammuz (4th month) June-July, Av (5 month) July-August, Elul (6 month) August-September, Tishrei (7th month) September-October, Heshvan or Cheshvan (8th month) October-November, Kislev (9th month) November-December, Tevet (10th month) December-January, Shevat (11th month) January-February, Adar (12th month) February-March.
Western Christian liturgical calendars are based on the cycle of the Roman Rite of the Catholic Church, including Lutheran, Anglican, and other Protestant calendars since this cycle pre-dates the Reformation. Generally, the liturgical seasons in western Christianity are Advent, Christmas, Ordinary Time (Time after Epiphany), Lent, Easter, and Ordinary Time (Time after Pentecost or after Trinity).
From the Latin adventus, "arrival" or "coming", the first season of the liturgical year begins four Sundays before Christmas and ends on Christmas Eve. Historically observed as a "fast", its purpose focuses on preparation for the coming Christ. Although often conceived as awaiting the coming of the Christ-child at Christmas, the modern Lectionary points the season more toward eschatological themes--awaiting the final coming of Christ, when "the wolf shall live with the lamb" (Isaiah 11:6) and when God will have "brought down the powerful from their thrones, and lifted up the lowly" (The Magnificat, Luke 1:52)--particularly in the earlier half of the season. This period of waiting is often marked by the Advent Wreath, a garland of evergreens with four candles. Although the main symbolism of the advent wreath is simply marking the progression of time, many churches attach themes to each candle, most often 'hope', 'faith', 'joy', and 'love'.
Color: Violet, or in some traditions Blue. On the third Sunday of Advent, also called Gaudete Sunday, Rose/Pink is used in some places.
Although the Roman Catholic rite omits the "Gloria in Excelsis" during Masses of the season (as opposed to Mass of a feast), "Alleluia" remains (although the traditional Catholic rite has only the Gradual without an "Alleluia", except on Sunday).
Whereas in the Roman Catholic Church and the Evangelical Lutheran Church in America, Ordinary Time begins after the Epiphany, in some Anglican traditions (including the Church of England) the Christmas season is followed by an Epiphany season, which begins on the Eve of the Epiphany (on 6 January or the nearest Sunday) and ends on the Feast of the Presentation (on 2 February or the nearest Sunday). Ordinary Time then begins after this.
"Ordinary" comes from the same root as our word "ordinal", and in this sense means "the counted weeks". In the Roman Catholic Church and in some Protestant traditions, these are the common weeks which belong to the seasons also known as the season after Epiphany and the same season after Pentecost. It consists of either 33 or 34 Sundays, depending on the year. In the modern Roman Rite, the first portion of Ordinary Time extends from the day following the Feast of the Baptism of Christ until the day before Ash Wednesday (the beginning of Lent). This first installment has anywhere from three to eight Sundays, depending on how early or late Easter falls. In other traditions, including Protestant ones, Ordinary Time may start as early as the day after Epiphany or as late as the day after Candlemas.
The terminology of "Ordinary Time" replaces the older language of the Seasons of "Time After Epiphany" and "Septuagesima" (pre-Lenten season), still used by Catholics who observe the Tridentine liturgy and by some Protestants.
In the Tridentine form of the Roman Rite, the Time after Epiphany can have anywhere from one to six Sundays, with Septuagesima as a 17-day season beginning nine Sundays before Easter and ending on the day before Ash Wednesday. Any omitted Sundays after Epiphany are transferred to the Time after Pentecost and celebrated between the Twenty-Third Sunday and the Last Sunday. If, however, there are not enough Sundays in the year to accommodate all such Sundays, then the one which would otherwise occur on Septuagesima Sunday is celebrated on the previous day (Saturday); in the case of Easter falling so late that there are only 23 Sundays After Pentecost, the Mass for the 23rd Sunday was celebrated on the day before the Last Sunday after Pentecost, until Pope John XXIII decreed in 1960 that the displaced Sunday Mass should be dropped for that year. During Septuagesima, certain customs of Lent are adopted, including the suppression of the "Alleluja" and, on Sundays, the Gloria, and the vestments are violet.
Color: Green (except, as mentioned, in the Tridentine pre-Lenten season).
Lent is a major fast taken to prepare for Easter. It begins on Ash Wednesday and ends on Holy Saturday, at the end of Holy Week. There are forty days of Lent, as the six Sundays in Lent are not counted. In the Roman rite of the Catholic Church, the Gloria and Te Deum are not used in the Mass and Divine Office, except on Feasts, and the word Alleluia is never said, either being omitted or replaced with "Praise to you, O Lord, King of eternal glory". Before the 1970 reforms, the last two weeks of Lent in the Catholic Church were known as Passiontide. During this season, the Gloria Patri is suppressed except after the Psalms in the Divine Office, the readings begin to focus even more on the Passion of Christ, and, most noticeably, the crucifixes and images of the saints are covered with violet cloth. On the Friday before Good Friday is the Feast of the Seven Sorrows of the Blessed Virgin Mary. Should the Feasts of St. Joseph or the Annunciation fall during Holy Week, they are transferred to the week following Easter.
Color: Violet. In some traditions, Rose may be used on the 4th Sunday of Lent, called Laetare Sunday.
The Easter Triduum consists of:
Easter is the celebration of Jesus' resurrection. The date of Easter varies from year to year, according to a lunar-calendar dating system (see computus for details). In the modern Roman rite calendar, the Easter season extends from the Easter Vigil through Pentecost Sunday. In the older calendars, which include an Octave of Pentecost, Eastertide lasts until None of Ember Saturday.
In the Roman Rite tradition, the Easter octave allows no other feasts to be celebrated or commemorated during it; but if Easter fell on 25 April (its latest possible date), the Greater Litanies, which were part of the liturgy of that date in earlier forms of the Roman Rite, were said on the following Tuesday.
Ascension Thursday, which celebrates the return of Jesus to heaven following his resurrection, is the fortieth day of Easter, but, in places where it is not observed as a Holy Day of Obligation, it is transferred to the following Sunday.
Pentecost is the fiftieth day, and celebrates the sending of the Holy Ghost to the Apostles. Pentecost is commonly seen as the birth of the Church.
Color: White or Gold, except on Pentecost, on which the color is Red.
Ordinal (ordinal for "counting" as these are "counting weeks" after Pentecost) Time resumes after the Easter Season, on Pentecost Monday, and ends on the Saturday before the First Sunday of Advent. In the ancient, Tridentine form of the Roman Rite, the Sundays in this part of the year are listed as "Sundays after Pentecost" by Roman Catholics; the Eastern Orthodox and some Protestants still adhere to this terminology. The first Sunday after Pentecost is Trinity Sunday and in many traditions the last Sunday of Ordinary Time is the Feast of Christ the King.
Variations during this season include:
Observed by Roman Catholics and some Anglicans on August 15. On this date, which is the same as the Eastern tradition of the Dormition, the bodily Assumption of Mary into heaven is celebrated. This feast day is perhaps the oldest feast day in the Christian Church, being celebrated in both the East and the West. The Roman Catholic teaching on this feast was defined as dogma on November 1 1950 by Pope Pius XII in the Papal Bull, Munificentissimus Deus.
In the Anglican and Lutheran traditions, as well as a few others, August 15th is celebrated as St. Mary, Mother of the Lord.
The Church of England uses a liturgical year that is in most respects identical to that of the Catholic Church. While this is less true of the calendars contained within the Book of Common Prayer and the Alternative Service Book (1980), it is particularly true since the Anglican Church adopted its new pattern of services and liturgies contained within Common Worship, in 2000. Certainly, the broad division of the year into the Christmas and Easter seasons, interspersed with periods of Ordinary Time, is identical, and the majority of the Festivals and Commemorations are also celebrated, with some obvious exceptions, chiefly that of the Assumption.
The Book of Common Prayer contains within it the traditional Western Eucharistic lectionary which traces its roots to the Comes of St. Jerome in the 5th century. Its similarity to the ancient lectionary is particularly obvious during Trinity season (Sundays after the Sunday after Pentecost), reflecting that understanding of sanctification (see a proposed rationale for Trinity season).
The Liturgical year in the Eastern Orthodox Church is characterized by alternating fasts and feasts, and is in many ways similar to the Roman Catholic year described above. However, Church New Year (Indiction) traditionally begins on September 1, rather than the first Sunday of Advent. It includes both feasts on the Fixed Cycle and the Paschal Cycle (or Moveable Cycle). The most important feast day by far is the Feast of Pascha (Easter)—the Feast of Feasts. Then the Twelve Great Feasts, which commemorate various significant events in the lives of Jesus Christ and of the Theotokos (Virgin Mary).
The majority of Orthodox Christians follow the Julian Calendar in calculating their ecclesiastical feasts, though many have adopted a Revised Julian Calendar, preserving the Julian calculation for feasts on the Paschal Cycle, but using the modern Gregorian Calendar to calculate those feasts which are fixed according to the calendar date. From 1900 until 2100, there has been a thirteen-day difference between the Julian and the Gregorian calendars. In some Eastern Orthodox countries certain civil holidays are calculated according to the Julian Calendar. Thus, for example, Christmas is celebrated on January 7 in these countries. The computation of the day of Pascha (Easter) is, however, computed according to the Julian Calendar, even by those churches which observe the Revised Julian Calendar.
There are four fasting seasons during the year: The most important fast is Great Lent which is an intense time of fasting, almsgiving and prayer, extending for forty days prior to Palm Sunday and Holy Week, as a preparation for Pascha. The Nativity Fast (Winter Lent) is a time of preparation for the Feast of the Nativity of Christ (Christmas), but whereas Advent in the West lasts only four weeks, Nativity Fast lasts a full forty days. The Apostles' Fast is variable in length, lasting anywhere from eight days to six weeks, in preparation for the Feast of Saints Peter and Paul (June 29). The Dormition Fast lasts for two weeks from August 1 to August 14 in preparation for the Feast of the Dormition of the Theotokos (August 15). The liturgical year is so constructed that during each of these fasting seasons, one of the Great Feasts occurs, so that fasting may be tempered with joy.
In addition to these fasting seasons, Orthodox Christians fast on Wednesdays and Fridays throughout the year (and some Orthodox monasteries also observe Monday as a fast day). Certain fixed days are always fast days, even if they fall on a Saturday or Sunday (in which case the fast is lessened somewhat, but not abrogated altogether); these are: The Decollation of St. John the Baptist, the Exaltation of the Cross and the day before the Epiphany (January 5th). There are several fast-free periods, when it is forbidden to fast, even on Wednesday and Friday. These are: the week following Pascha, the week following Pentecost, the period from the Nativity of Christ until January the 5th and the first week of the Triodion (the week following the 33rd Sunday after the Pentecost).
The date of Pascha is central to the entire ecclesiastical year,determining not only the date for the beginning of Great Lent and Pentecost, but affecting the cycle of moveable feasts, of scriptural readings and the Octoechos (texts chanted according to the eight ecclesiastical modes) throughout the year. There are also a number of lesser feasts throughout the year that are based upon the date of Pascha. The moveable cycle begins on the Zacchaeus Sunday (the first Sunday in preparation for Great Lent or the 33rd Sunday after Pentecost as it is known), though the cycle of the Octoechos continues until Palm Sunday.
The date of Pascha affects the following liturgical seasons:
Some of these feasts follow the Fixed Cycle, and some follow the Moveable (Paschal) Cycle. Most of those on the Fixed Cycle have a period of preparation called a Forefeast, and a period of celebration afterward, similar to the Western Octave, called an Afterfeast. Great Feasts on the Paschal Cycle do not have Forefeasts. The lengths of Forefeasts and Afterfeasts vary, according to the feast.
NOTE: In Eastern practice, should this feast fall during Holy Week or on Pascha itself, the feast of the Annunciation is not transferred to another day. In fact, the conjunction of the feasts of the Annunciation and Pascha, known as "Kyriou-Pascha," is considered an extremely wondrous event.
Every day throughout the year commemorates some saint or some event in the lives of Christ or the Theotokos. When a feast on the moveable cycle occurs, the feast on the fixed cycle that was set for that calendar day is transferred, with the propers of the feast often being chanted at Compline on the nearest convenient day.
In addition to the Fixed and Moveable Cycles, there are a number of other liturgical cycles in the ecclesiastical year that affect the celebration of the divine services. These include, the Daily Cycle, the Weekly Cycle, the Cycle of Matins Gospels, and the Octoechos.