Easter, Date of

Easter, Date of

Christians celebrate Easter on the Sunday following the first full moon that occurs on or after the spring equinox, which in the Northern Hemisphere occurs around March 21. Nevertheless, they generally don't celebrate it on the same day. Western Christians, that is, Roman Catholics and Protestants, follow the above rule in calculating the date of Easter, and use the same calendar system that they use in everyday life to determine the date of the spring equinox. Although the date of Easter changes from year to year, it always falls sometime between March 22 and April 25. Orthodox and other Eastern Christians - those Christians whose traditions of worship developed in north Africa, eastern Europe and the Middle East-rely on an older calendar system for the date of the spring equinox. Moreover, they also insist that Easter fall after the Jewish holiday of Passover. For these Christians Easter may fall anywhere between April 4 and May 8. Historians believe that the earliest Easter celebrations took place around the middle of the second century. When Christians started to commemorate the yearly anniversary of Jesus' crucifixion and resurrection, they looked to Christian scripture for clues about the dates on which these events occurred (for more on crucifixion, see Cross). All four biblical accounts of the Resurrection agree that it happened on the Sunday following the start of the Passover festival. According to the Jewish calendar, Passover begins on the fifteenth day of the month of Nisan. Yet the Jewish calendar differs in important ways from the calendar systems used by many other ancient peoples. Trying to translate the date of Passover into these other calendar systems has created nearly two millennia of conflict and confusion among Christians as to the correct date of Easter.

The Challenge of the Calendar

It takes the earth 365.2422 days to complete its orbit around the sun. We call this period of time, based entirely on solar rhythms, a year. The moon runs through its cycle, from full to new to full again, in 29.5306 days. Calendar makers have named this unit of time a lunar month. These two units of time do not mesh well with each other. During the 365.2422 days of the solar year, the moon will complete twelve full cycles and will journey eleven days into the next lunar cycle. Moreover, the naturally occurring unit of time that we call a day doesn't divide evenly into either the solar year or the lunar month.

Throughout history calendar makers have proposed various formulas to reconcile these differences. Some calendar systems rely entirely on the yearly solar cycle and accept the fact that the stages of the moon will occur on different days from month to month. Extra days may be added from time to time to adjust for the additional 0.2422 day included in each solar year. Other calendar systems base their months on the lunar cycle and accept the fact that the months will drift from season to season as a result of the difference between the yearly solar and monthly lunar cycles. The history of calendar systems in the Western world reveals a long struggle to harmonize the solar year and the lunar month.

The Jewish Calendar

In addition to the solar and lunar cycles, the ancient Jews, who depended on agriculture and animal husbandry for their living, keenly observed another natural cycle, that is, the changing of the seasons. They developed a calendar system that tried to reconcile all three natural cycles. The Jewish calendar revolves around twelve lunar months, but also includes periodic readjustments to keep the solar and lunar cycles more or less in line. These readjustments take the form of an extra month added to some years which prevents the feast days from drifting forward in the seasons. Each month begins on the first day on which the new moon is visible in the sky. Thus Passover, which falls on the fifteenth of Nisan, always coincides with a full moon. Although this calendar system anchors Passover to the spring season, the holiday does float around a bit on the solar calendar. In our contemporary civil calendar, which is based on the solar year, Passover may fall anywhere between March 27 and April 24.

The ancient Jewish rule for determining the date of Passover stated that the festival was to begin at the close of the fourteenth day after the full moon that fell on or following the spring equinox. Since the Jews began each new day at sunset, the evening that followed the afternoon of the fourteenth was considered the start of the fifteenth day of Nisan. Preparations for Passover took place on the afternoon of the fourteenth, and the holiday itself began after sundown, which marked the beginning of the fifteenth of Nisan. Nevertheless, the Jews did not possess a very accurate astronomy, so they tended to base the timing of Passover more on seasonal changes, which directly affected their livelihood, than on astronomical observations.

The First Easter Celebrations

Christian scripture states that Jesus' crucifixion and resurrection took place around Passover. When Christians first began to commemorate these events this timing posed several problems for them. First, as Christianity spread to increasing numbers of non-Jews, its adherents found themselves less and less familiar with the Jewish calendar system. Some Christians may have felt embarrassed to ask their Jewish neighbors about the date of Passover in order to plan the most important festival in their own religious calendar. Others felt superior to the Jews and therefore thought that Christianity should not have to rely on the Jewish calendar. In addition, the diverse ethnic and religious groups that made up the ancient Mediterranean world employed a variety of different calendars. This made it even more difficult for Christian officials to set a standard date for Easter. So local Christian communities had to discover the date of Passover and translate it into their own calendar system in order to celebrate Easter.

In Asia Minor, now the modern nation of Turkey, Greek-speaking Christians relied on their own version of the official Roman calendar. When they began to commemorate the anniversary of the Crucifixion and Resurrection, some of these Christians simply timed their celebration to coincide with the Jewish holiday of Passover. Others did not want to rely on their Jewish neighbors to tell them when Passover would occur that year, and so assigned their Easter celebrations a specific date in their own calendar, namely, the fourteenth of Artemisios, the first month of spring. This translates to April 6 in our own calendar system. Amidst the welter of time-reckoning systems used by the subjects of the Roman Empire, the official Roman calendar - introduced by the Roman emperor Julius Caesar in 45 B.C. and known as the Julian calendar - furnished a potentially unifying factor. In the third century scattered Christian communities in northern Italy, Gaul, Spain, Syria, and Asia Minor began to celebrate Easter using a fixed date in the Julian calendar. They believed that the Crucifixion had taken place on the Julian calendar date of March 25, which was also the official date of the spring equinox in that calendar system. So, they scheduled their Easter celebrations on March 25.

Yet each of these methods of calculating the date of Easter fell short of completely reproducing the timing of Jesus' crucifixion and resurrection as recounted in Christian scripture. Since the Julian calendar date of Jesus' death and rising had not been recorded by witnesses, many Christians felt that assigning Easter a date in this calendar was inappropriate. Moreover, three of the four accounts of Jesus' death given in Christian scripture state that it took place on Passover, while the fourth implies that it took place on the afternoon before Passover, as the lambs were being sacrificed for the festival.

In spite of this slight discrepancy all four scriptural accounts of Jesus' resurrection agree that it took place on the first day of the Jewish week, a Sunday. Weekly Christian worship services were scheduled on Sunday in honor of this event. Therefore some Christian leaders believed that Easter should also be celebrated on a Sunday. Those who argued for a Sunday celebration felt that Easter should occur on the Sunday following Passover. They criticized those who celebrated on Passover itself for ignoring the importance of the Sunday Resurrection. In Rome the earliest celebration of Easter on the Sunday following the start of Passover took place around the year 165, though other communities may have begun the practice before that time. Christian authorities in Rome became strong advocates of this method of setting a date for Easter, and those communities that looked to Rome for leadership adopted this model.

Historians still debate when and where the first Easter celebrations took place (see also Pascha). Historical evidence uncovered to date suggests that they took place in Asia Minor around the middle of the second century and that they coincided with the Jewish festival of Passover. Nevertheless some scholars believe that earlier celebrations may have taken place in other Christian communities. The Asia Minor Christians who celebrated Easter on Passover became known as Quatrodecimans, or "fourteeners," to Latin-speaking Christians because their Easter observances began with a fast on the fourteenth of Nisan and coincided with the Jewish Passover. The Quatrodecimans and the Romans battled one another over the correct date on which to celebrate Easter. At one point Roman officials threatened to excommunicate - that is, to ban from full membership in the Christian Church - anyone who followed the quatrodeciman system.

Resolving Conflicts in Easter Dating Systems

In 325 A.D. Christian leaders from all corners of the globe converged on Nicaea, a small town near Constantinople, now Istanbul, Turkey. The Roman emperor Constantine convened this gathering, known as the Council of Nicaea, in order that Christian officials come to agreement on several important issues concerning Christian doctrine and worship. Constantine issued several pronouncements concerning the proper date of Easter based on the conclusions reached during this series of meetings. The Emperor decreed that henceforth all Christians should celebrate Easter on the same date. He also called for the complete separation of the timing of Easter from that of Passover. This decision further separated the Christian and Jewish faiths, and may have been motivated by rising feelings of anti-Semitism, that is, prejudice against Jews and other Middle Eastern peoples. Constantine also called for Christians to celebrate Easter after the spring equinox, saying that to schedule the festival beforehand was a grave error.

These decisions created new difficulties for Christians, since astronomy was not a very advanced science in those days and people weren't sure exactly when the spring equinox occurred. In 45 B.C., when the Julian calendar was first introduced, the spring equinox fell on March 25. The inventors of the Julian calendar, however, had calculated the solar year to be 365.25 days long. In fact, the solar year lasts 365.2422 days. While this difference only amounts to eleven minutes and fourteen seconds every year, each passing year compounds the error. As a result, the dates on the calendar slowly began to separate from the events of the solar year. By 325, the year that Christian leaders attended the Council of Nicaea, the spring equinox actually fell on March 21. Astronomers from the city of Alexandria, Egypt, realized this fact and publicized the correct date. Many Christian communities in the Middle East and north Africa accepted the Alexandrian date for the equinox. Roman Christians, and those who looked to Rome for leadership, tended to stick with the old Roman date for the equinox, March 25.

For several centuries Easter celebrations still took place on a variety of dates, in spite of Constantine's decrees. Many Christian communities attempted to celebrate Easter after the spring equinox, but disagreed on when the equinox occurred. Furthermore, in Ireland and the British Isles Christian authorities felt no obligation to accept the decrees of Nicaea, since no representative from their lands had taken part in that Council. When Christian missionaries under the jurisdiction of Rome showed up in the late sixth century, they found these Celtic Christians adhering to their own calendar. Tension came to a head around the mid-seventh century, when the Anglo-Saxon king Oswy, a Celtic Christian, found himself celebrating Easter a week earlier than his wife Eanfled, who followed the teachings of the Roman Church. Eventually Oswy called a council of Roman and Celtic church leaders throughout the British Isles, known to historians as the Synod of Whitby. Representatives from each side presented arguments for the adoption of their calendar system. In the end Oswy ruled in favor of the Roman system of dating Easter, decreeing that it be adopted throughout the land.

The Middle Ages

By the early Middle Ages a general agreement finally emerged among Christians that Easter should be scheduled for the first Sunday after the full moon falling on or after the spring equinox, which most Christians now agreed occurred on March 21. If the full moon were to fall on a Sunday, then Easter would be celebrated the following Sunday. This formula for setting the date of Easter is often attributed to the Council of Nicaea, and may well have originated there, although no records have survived to document that fact. It echoes Jewish regulations for setting the date of Passover, which in ancient times was supposed to begin on the first full moon after the equinox.

Church astronomers devised complicated tables for determining in advance the calendar date of Easter. These tables attempted to match up the solar cycle of the year with the lunar cycles of the months, and then mesh them with the seven-day cycle of the week so as to predict in advance the exact calendar date on which Easter would fall. This task proved difficult and the tables complex. As the Middle Ages slid by, these arrangements became more and more unsatisfactory. The original flaw in the Julian calendar once again took effect, driving a slow-moving wedge between the events of the solar year and the dates of the calendar.

The Gregorian Calendar Reform

Although Alexandrian astronomers had correctly identified the date of the spring equinox in the early fourth century, the inherent error in the Julian calendar system meant that the calendar was slowly falling behind the events of the solar year. Thus by the sixteenth century the calendar lagged ten days behind, with the result that the spring equinox fell on March 11 rather than March 21. Growing concern that the flaws in the Julian calendar might lead them to celebrate Easter on the wrong day prompted Roman Catholic officials to investigate the possibility of calendar reform. They reviewed several proposals for a new calendar system and finally settled on one of them, named the Gregorian calendar in honor of the reigning pope, Gregory XIII. In 1582 Pope Gregory XIII approved of the new calendar system and called for its immediate and universal adoption. In order to bring the spring equinox back to the traditional date of March 21, eleven days were dropped from the calendar. Thus in the year 1582 October fourth was followed by October 15 in all countries that accepted the new calendar.

Europe's Roman Catholic countries immediately took up the Gregorian calendar. Portugal, Spain, and Italy, for example, installed it in 1582, the same year of the Pope's proclamation. The unfortunate timing of the calendar reform, however, led to its initial rejection in much of northern Europe. The Roman Catholic Church introduced the Gregorian calendar in the same century that the Reformation, a western European religious reform movement, tore the religious fabric of the continent apart. Those countries that had embraced the religious reforms and were now primarily Protestant refused to accept the new calendar for fear of seeming to accept the authority of the pope. So they went on celebrating Easter according to the old calendar. Once again, Christians in different parts of the world and branches of the church celebrated Easter on different days.

In spite of the religious controversy that surrounded it, scientists across Europe recognized the new, Gregorian calendar to be far more accurate than the old Julian calendar. So, one by one, the nations that had initially refused the new calendar decided to accept it. Belgium instituted the Gregorian calendar in 1584. Most of the German Catholic states switched to the new calendar by the same year. Hungary followed suit in 1587. Denmark and Protestant Germany delayed until 1700, however. Great Britain finally made the change in 1752, along with her American colonies. Sweden followed close behind in 1753. As western European countries established military and economic dominance around the globe, they influenced others to adopt their calendar system. Japan started to use the Gregorian calendar in 1873. China finalized its adoption of the Gregorian calendar in 1949.

Continuing Orthodox Use of the Julian Calendar

Meanwhile, controversy concerning the merits of the Gregorian calendar still simmered in the Orthodox countries of eastern Europe. Religious authorities in these countries had rejected the Gregorian calendar at the time of its introduction in western Europe. They based their refusal on religious grounds, stating that such a major change could not be instituted by a single Christian official, but rather must be approved by a church-wide council similar to the one held in Nicaea. By the early twentieth century, the governments of these eastern European countries began to adopt the Gregorian calendar for civil use. The former Soviet Union adjusted to the new calendar in 1918. Greece began to use the Gregorian calendar in 1923. Nevertheless, religious officials in these predominantly Orthodox countries continued to rely on the Julian calendar to set the date of Easter.

Even today Orthodox Christians around the world maintain the ancient tradition of setting the date of Easter and its related festivals according to the Julian calendar, although many Orthodox Christians use the Gregorian calendar dates for other religious holidays. Orthodox Christians in Finland, who celebrate Easter according to the Gregorian calendar, provide the only exception to the rule. The Julian calendar currently trails thirteen days behind the Gregorian calendar. Thus, when the Julian calendar reaches March 21, the traditional date of the spring equinox, the Gregorian calendar counts the day as April 3. This means that Orthodox Easter tends to occur somewhat later in the spring than does Western Easter. Nevertheless, on occasion the Western and Orthodox Easters coincide, uniting millions of Christians around the world in the common celebration of their most important holiday.

In Ethiopia the situation is even more complex. There a modified version of the Julian calendar still serves as the civil calendar used by all, as well as the religious calendar used by Ethiopian Orthodox Christians. This calendar is based on twelve months of thirty days each, as well as a thirteenth month of five or six days, depending on whether or not it is a leap year. In addition, the new year begins in September rather than January. Finally, the Ethiopian calendar lags about eight years behind both the standard Julian and Gregorian calendars. Long ago Roman Catholic and Ethiopian Orthodox religious officials disagreed over the date of the creation of the world. This difference in opinion is said to account for the fact that Ethiopia numbers the current year differently than does the rest of the world. For example, on January 1, 1999, calendars in Ethiopia read Tahisas (the fourth month) 23, 1991.

Proposals for a Unified Easter

In recent years some church leaders have advocated reuniting Christian Easter celebrations. The World Council of Churches has proposed the following three principles for fixing the date of Easter, which they hope will eventually be adopted by all Christians. First, Christians will maintain the rule set by the Council of Nicaea that Easter falls on the Sunday after the full moon occurring on or after the spring equinox. Second, they will set the date of the equinox with the use of modern astronomical and scientific measures. Third, they will base all reckoning that varies due to one's location on the earth on the meridian of Jerusalem, the city where Jesus' crucifixion and resurrection took place.

Further Reading

Achelis, Elisabeth. The Calendar for Everybody. 1943. Reprint. Detroit, MI: Omnigraphics, 1990. Aveni, Anthony. Empires of Time. New York: Kodansha Books, 1995. Bellenir, Karen. Religious Holidays and Calendars. Second edition. Detroit, MI: Omnigraphics, 1998. Blackburn, Bonnie, and Leofranc Holford-Strevens. The Oxford Companion to the Year. Oxford, England: Oxford University Press, 1999. Bradshaw, Paul F. The Search for the Origins of Christian Worship. New York: Oxford University Press, 1992. Bradshaw, Paul F. "The Origins of Easter." In Paul F. Bradshaw and Lawrence A. Hoffman, eds. Passover and Easter: Origin and History to Modern Times. Two Liturgical Traditions series, volume 5. Notre Dame, IN: University of Notre Dame Press, 1999. Duncan, David Ewing. Calendar. New York: Avon, 1998. Eisenberg, Azriel. The Story of the Jewish Calendar. New York: Abelard-Schuman, 1958. Talley, Thomas J. The Origins of the Liturgical Year. Collegeville, MN: Liturgical Press, 1986.

Web Sites

A summary of the events leading up to and including the Synod of Whitby, by Louise Elaine Burton, posted on Christianity Today's web site:

"The Western and Ethiopian Calendars," an article by Y. M. W. Kirios published in the Ethiopian Review 6,1 (1996). Available online for a fee through Northern Light at: www.northernlight.com/ Document ID: GG1998042906

"The Calendar of the Orthodox Church," an article by Lewis Patsavos, Ph.D., posted on the Greek Orthodox Archdiocese of America in New York, NY, web site at: Church/calendar.html
Encyclopedia of Easter, Carnival, and Lent, 1st ed. © Omnigraphics, Inc. 2002