How the Date of the Celebration of Easter Came to Be

The Hebrew calendar, which is still in use to this day, is based on the Anno Mundi (“in the year of the world”) premise. Anno Mundi dates events from the beginning of the creation of the earth as calculated as best as possible through scripture.

Ancient civilizations derived their calendars based on the reign of kings or the cycles of the seasons as set by their various gods. In Mesopotamia one would have dated an event as “five years from the reign of King Shulgi”.

In Egypt, it would have been “three years after the last Opet Festival of Ramesses who was the second of that name”. Or perhaps “In the tenth year of the reign of Ramesses who triumphed at Kadesh”. This method of dating was continued by the Romans who counted their years according to three different systems in different eras including from the founding of Rome, and by emperors who ruled at a point in time.

It was Julius Caesar who reformed the calendar and renamed the months during his reign from 49-44 BCE (Before Common Era (BCE) or before Christ (BC)). This calendar remained in use, with periodic revisions, until 1582 CE (Common Era). This is the same as AD (anno Domini), which means “in the year of the Lord” in Latin. In 1582 CE, Pope Gregory XIII instituted the Gregorian calendar which is also still in use in the present day. Christians used the Anno Mundi calendar and the Roman calendar in the early years of the faith. In 525 CE, a new concept in dating was introduced by a Christian monk named Dionysius Exiguus (470-544 CE) which provided the foundation for the move to the BC/AD system.

Dionysius Exiguus invented the concept of Anno Domini (“in the year of our Lord”) or AD time in an effort to stabilize the date of the celebration of Easter. While he was working on this problem, Christians of the church of Alexandria were dating events from the beginning of the reign of the Roman emperor Diocletian (284 CE). Ironically, this emperor often persecuted members of the new Christian faith. Dionysius Exiguus’s goal was to bring the eastern and western churches into agreement on a single day on which all Christians would celebrate Easter.

This goal had been decided upon by Constantine the Great at the Council of Nicea in 325 CE, but that goal had not yet been achieved. Dionysius Exiguus ultimately succeeded in changing the system of dating years from the Roman system and the Alexandrian system. This new system is centered on the Christian era starting with the birth of Jesus of Nazareth. This choice also eliminated another Christian problem, which was the dating historical events based on the reign of an emperor who had killed so many Christians. [1]

The only problem with this dating system was that no one actually knew when exactly Jesus of Nazareth was born. Dionysius Exiguus himself did not know when Jesus was born, and his system made no claims or credits for dating that event definitively. He seems to have arrived at his calculations through a reliance on scripture and the known history of the time to create a Christian calendar which would be acceptable to both the western and eastern churches of the time for the celebration of Easter.

Dionysius Exiguus never made the claim that he knew the date of Jesus’s birth.  He did not begin his quest to reform the calendar for the purpose of accurately dating the birth of Jesus of Nazareth.  He did it in accordance with the wishes of the pope of the time who wanted Constantine’s vision realized.

The Easter celebration of the resurrection was considered the most important celebration of the church. Constantine, and those in power who followed him, wanted Easter observed by all churches on the same day. It was Dionysius Exiguus’s job to make that happen. He tried to do this by making a new calendar system which involved calculating the date of Jesus’s birth. This was the means to his desired end, not the target end in itself.

The Bible does not specifically identify the year when Jesus was born.  It does, however, provide sufficient information to identify a relatively narrow range of dates. There is no true proof or agreement with Christian theologians on this matter. It is complicated and difficult to understand. One version of the deduction path to the time of the birth of Jesus Christ goes like this:

It was after Archelaus began to rule in Judea in 4 BC when Jesus returned to Israel from Egypt and settled in Nazareth. Before taking Jesus from Nazareth to Jerusalem for the Passover feast when Jesus was twelve years old (Luke 2:42). The Bible says that Joseph and Mary “went to Jerusalem every year at the feast of the Passover” (Luke 2:41)- every year.” This means that at least three prior Passover visits to Jerusalem before the visit mentioned in Luke 2:41 that took place when Jesus was twelve years old. If there had been only three prior Passover visits and the one mentioned in Luke 2:41 is the fourth, and if Archelaus began to rule in Judea just before Jesus settled in Nazareth, four years would have passed since Archelaus’ rule began in 4 BC, so the year would have theoretically been 0 AD. There is however, no such thing as a “zero” year. In this system, the year Christ was born is 1 A.D., and the year preceding it is 1 B.C.

Since Jesus is indicated as being twelve years old at this time, it would mean that Jesus was born in 12 BC. If there had been four prior Passover visits and the one mentioned in Luke 2:41 is the fifth, five years would have passed since Archelaus’ rule began in 4 BC, so the year would have been 1 AD. Since Jesus is indicated as being twelve years old at this time, it would mean that Jesus was born in 11 BC. Similarly, if there had been 5, 6, 7, 8, 9, 10, 11 prior Passover visits, Jesus would have been born in 10 BC, 9 BC, 8 BC, 7 BC, 6 BC, 5 BC, 4 BC, respectively. Since the “census” mentioned in Luke 2:2 took place in 8 BC, Jesus was born between 8 BC and 4 BC.[2] There are other versions of this calculation out there, but the results are similar[3].

The BC/AD system is fundamentally flawed in that it misrepresents the birth of Jesus by approximately 6 years, depending on your sources. The year of Jesus’s birth differs depending on which Gospel one reads. While the Gospel of Matthew states in chapter 2:1 that Jesus was born during the reign of Herod the Great, the Gospel of Luke states in chapter 2:1-2 that Jesus was born during the first census of the rule of Quirinius, governor of Syria. According to ancient sources, the date of this census is about 6 CE. The Bible is internally inconsistent regarding the year of Jesus’ birth.[4]  6 BC is most often considered the best educated and defensible guess as to the year of Jesus’s birth.

Fixing the date on which the Easter was to be observed and celebrated triggered a major controversy in early Christianity in which an Eastern and a Western position can be delineated. The dispute, known as the Paschal controversies, was not definitively resolved until the 8th century. Christians observed the day of the Crucifixion on the same day that Jews celebrated the Passover offering which was the 14th day after the first full moon of spring. Resurrection, then, was observed 3 days later, regardless of the day of the week.

In the West, the Resurrection of Jesus was celebrated on the first day of the week, Sunday, when Jesus had risen from the dead. Consequently, Easter was always celebrated on the first Sunday after the 14th day of the month. Increasingly, the churches opted for the Sunday celebration, and the Quartodecimans (“14th day” proponents) remained a minority. In the end, it was the Council of Nicaea in 325 that decreed that Easter should be observed on the first Sunday following the first full moon after the spring equinox (March 21). Easter, therefore, can fall on any Sunday between March 22nd  and April 25th .[5]

The first full moon of April (the pink moon) is always the 3rd full moon of the year. Jesus was resurrected on the 3rd day after his crucifixion and that is what the Easter feast is all about. This year (2023) the first April full moon in the western hemisphere occurred on Thursday April 6th and Sunday the 9th is Easter Sunday, 3 days after the first full moon of April. The number 3 is a huge deal in Christianity and this Easter’s line up of the number 3 does not occur very often, making this year’s Easter celebration just a bit more special.

Happy Easter to you!

[1] LiveScience.com. Keeping time: The origin of B.C. and A.D.  Robert Coolman , Owen Jarus.  January 14, 2022

[2] Bible Verse Study. When was Jesus Christ Born? Author not cited. 2022

[3] Biblical Archeology Society. When Was Jesus Born—B.C. or A.D.? How the divide between B.C. and A.D. was calculated.  Megan Sauter. December 4, 2021

[4] World History Encyclopedia. The Origin & History of the BCE/CE Dating System. Joshua J. Mark. March 27, 2017

[5] Britannica. Easter Holiday. Hans J. Hillerbrand. April 7, 2003