Date of the birth of Jesus

The date of the birth of Jesus is not stated in the gospels or in any historical sources and the evidence is too incomplete to allow for consistent dating. However, most biblical scholars and ancient historians believe that his birth date is around 4 to 6 BC. Two main approaches have been used to estimate the year of the birth of Jesus: one based on the accounts in the Gospels of his birth with reference to King Herod's reign, and the other by subtracting his stated age of "about 30 years" when he began preaching.

Aside from the historiographical approach of anchoring the possible year to certain independently well-documented events mentioned in Matthew and Luke, other techniques used by believers to identify the year of the birth of Jesus have included working backward from the estimation of the start of the ministry of Jesus and assuming that the accounts of astrological portents in the gospels can be associated with certain astronomical alignments or other phenomena.

The common Christian traditional calendar date of the birthdate of Jesus was 25 December, a date asserted officially by Pope Julius I in 350 AD, although this claim is dubious or otherwise unfounded. The day or season has been estimated by various methods, including the description of shepherds watching over their sheep. In the third century, the precise date of Jesus's birth was a subject of great interest, with early Christian writers suggesting various options. Around AD 200, Clement of Alexandria wrote:

"There are those who have determined not only the year of our Lord's birth, but also the day; and they say that it took place in the 28th year of Augustus, and in the 25th day of [the Egyptian month] Pachon [20 May]... Further, others say that He was born on the 24th or 25th of Pharmuthi [20 or 21 April]."

The early Christian writer Lactantius wrote "the east is attached to God because he is the source of light and the illuminator of the world and he makes us rise toward eternal life". It is for this reason that the early Christians established the direction of prayer as being eastward, towards the rising sun. A late fourth-century sermon by Saint Augustine explains why the winter solstice was a fitting day to celebrate Jesus's birth:

"Hence it is that He was born on the day which is the shortest in our earthly reckoning and from which subsequent days begin to increase in length. He, therefore, who bent low and lifted us up chose the shortest day, yet the one whence light begins to increase."

Steven Hijmans of the University of Alberta wrote: "It is cosmic symbolism... which inspired the Church leadership in Rome to elect the southern solstice, December 25, as the birthday of Christ, and the northern solstice as that of John the Baptist, supplemented by the equinoxes as their respective dates of conception." The Christian treatise De solstitia et aequinoctia conceptionis et nativitatis Domini nostri Iesu Christi et Iohannis Baptistae ('On the solstice and equinox conception and birth of Our Lord Jesus Christ and John the Baptist'), from the second half of the fourth century, dates John's birth to the summer solstice and Jesus's birth to the winter solstice.

Nativity accounts
The nativity accounts in the New Testament gospels of Matthew and Luke do not mention a date or time of year for the birth of Jesus. Karl Rahner states that the authors of the gospels generally focused on theological elements rather than historical chronologies.

Both Luke and Matthew associate Jesus' birth with the time of Herod the Great. Matthew 2:1 states that "Jesus was born in Bethlehem of Judaea in the days of Herod the king". He also implies that Jesus could have been as much as two years old at the time of the visit of the Magi, because Herod ordered the murder of all boys up to the age of two years (Massacre of the Innocents), "in accordance with the time he had learned from the Magi" Matthew 2:16. In addition, if the phrase "about 30" in Luke 3:23 is interpreted to mean 32 years old, this could fit a date of birth just within the reign of Herod, who died in 4 BC according to most scholars.

Luke 1:5 mentions the reign of Herod shortly before the birth of Jesus. This Herod died in 4 BC. Luke 2:1-2 also places the birth during a census decreed by Caesar Augustus, when Quirinius was governing Judah. Some interpreters of Luke determine that this was the Census of Quirinius, which the Jewish historian Josephus described as taking place c. AD 6 in his book Antiquities of the Jews (written c. AD 93), by indicating that Cyrenius/Quirinius began to be the governor of Syria in AD 6 and a census took place during his tenure sometime between AD 6–7. Since Herod died a decade before this census, most scholars generally accept a date of birth between 6 and 4 BC. On the other hand, a census was not a unique event in the Roman Empire. For example, Tertullian argued that a number of censuses were performed throughout the Roman world under Sentius Saturninus at the same time. Some biblical scholars and commentators believe the two accounts can be harmonized, arguing that the text in Luke can be read as "registration before (πρώτη) Quirinius was governor of Syria", i.e., that Luke was actually referring to a completely different census, though this understanding of the Greek word has been rejected by scholars.

Backdating from the beginning of the ministry of Jesus
Another approach to estimating the year of birth is based on an attempt to work backwards from the point when Jesus began preaching, using the statement in Luke 3:23 that he was "about 30 years of age" at that time. Jesus began to preach after being baptized by John the Baptist, and based on Luke's gospel John only began baptizing people in "the fifteenth year of the reign of Tiberius Caesar" (Luke 3:1–2), which scholars estimate would place the year at about AD 28–29. By working backwards from this, it would appear that Jesus was probably born no later than 1 BC. Another theory is that Herod's death was as late as after the January eclipse of 1 BC or even AD 1 after the eclipse that occurred in 1 December BC.

Luke's date is independently confirmed by John's reference in John 2:20 to the Temple being in its 46th year of construction when Jesus began his ministry during Passover, which corresponds to around 27–29 AD according to scholarly estimates.

Dates based on the Star of Bethlehem
Most scholars regard the Star of Bethlehem account to be a pious fiction, of literary and theological value, rather than historical. Nonetheless, attempts have been made to interpret it as an astronomical event, which might then help date Jesus' birth through the use of ancient astronomical records, or modern astronomical calculations. The first such attempt was made by Johannes Kepler who interpreted the account to describe a great conjunction. Other astronomical events have been considered, including a close planetary conjunction between Venus and Jupiter in 2 BC.

Date of Herod's death
Most scholars concerning the date of Herod's death follow Emil Schürer's calculations published in 1896, which revised a traditional death date of 1 BC to 4 BC. Two of Herod's sons, Archelaus and Philip the Tetrarch, dated their rule from 4 BC, though Archelaus apparently held royal authority during Herod's lifetime. Philip's reign would last for 37 years, until his death in the traditionally accepted 20th year of Tiberius (AD 34), which implies his accession as 4 BC.

In 1998, David Beyer published that the oldest Latin manuscripts of Josephus’s Antiquities have the death of Philip in the 22nd year of Tiberius (and not the 20th year, as shown in later editions of the Antiquities). In the British Library, there is not a single manuscript prior to AD 1544 that has the traditionally accepted 20th year of Tiberius for the death of Philip. This evidence removes the main obstacle for a later date of 1 BC for the death of Herod. Beyer's arguments have been questioned by Raymond Jachowski, who argued that Beyer only used ill-attested Latin translations instead of the original Greek manuscripts, some of which date to the 13th and 11 centuries. Nevertheless, other scholars support the traditional date of 1 BC for Herod's death,   and argue that his heirs backdated their reigns to 4 or 3 BC to assert an overlapping with Herod's rule and bolster their own legitimacy, something that had already been done by a few rulers before them.

According to Dionysius Exiguus: the Anno Domini system
The Anno Domini dating system was devised in 525 by Dionysius Exiguus to enumerate the years in his Easter table. His system was to replace the Diocletian era that had been used in older Easter tables, as he did not wish to continue the memory of a tyrant who persecuted Christians. The last year of the old table, Diocletian Anno Martyrium 247, was immediately followed by the first year of his table, Anno Domini 532. When Dionysius devised his table, Julian calendar years were identified by naming the consuls who held office that year — Dionysius himself stated that the "present year" was "the consulship of Probus Junior", which was 525 years "since the incarnation of our Lord Jesus Christ". Thus, Dionysius implied that Jesus' incarnation occurred 525 years earlier, without stating the specific year during which his birth or conception occurred. "However, nowhere in his exposition of his table does Dionysius relate his epoch to any other dating system, whether consulate, Olympiad, year of the world, or regnal year of Augustus; much less does he explain or justify the underlying date."

Bonnie J. Blackburn and Leofranc Holford-Strevens briefly present arguments for 2 BC, 1 BC, or AD 1 as the year Dionysius intended for the Nativity or Incarnation. Among the sources of confusion are:
 * In modern times, Incarnation is synonymous with the conception, but some ancient writers, such as Bede, considered incarnation to be synonymous with the Nativity.
 * The civil or consular year began on 1 January, but the Diocletian year began on 29 August (30 August in the year before a Julian leap year).
 * There were inaccuracies in the lists of consuls.
 * There were confused summations of emperors' regnal years.

It is not known how Dionysius established the year of Jesus's birth. One major theory is that Dionysius based his calculation on the Gospel of Luke, which states that Jesus was "about thirty years old" shortly after "the fifteenth year of the reign of Tiberius Caesar" (AD 28/29), and hence subtracted thirty years from that date, or that Dionysius counted back 532 years from the first year of his new table. This method was probably the one used by ancient historians such as Tertullian, Eusebius or Epiphanius, all of whom agree that Jesus was born in 2 BC, probably following this statement of Jesus' age (i.e. substracting thirty years to AD 29). Alternatively, Dionysius may have used an earlier unknown source. The Chronograph of 354 states that Jesus was born during the consulship of Caesar and Paullus (AD 1), but the logic behind this is also unknown.

It has been speculated by Georges Declercq that Dionysius' desire to replace Diocletian years with a calendar based on the incarnation of Jesus was intended to prevent people from believing the imminent end of the world. At the time, it was believed by some that the resurrection of the dead and end of the world would occur 500 years after the birth of Jesus. The old Anno Mundi calendar theoretically commenced with the creation of the world based on information in the Old Testament. It was believed that, based on the Anno Mundi calendar, Jesus was born in the year 5500 (5500 years after the world was created) with the year 6000 of the Anno Mundi calendar marking the end of the world. Anno Mundi 6000 (approximately AD 500) was thus equated with the end of the world but this date had already passed in the time of Dionysius. The "Historia Brittonum" attributed to Nennius written in the 9th century makes extensive use of the Anno Passionis (AP) dating system which was in common use as well as the newer AD dating system. The AP dating system took its start from 'The Year of The Passion'. It is generally accepted by experts there is a 27-year difference between AP and AD reference.

Pope Benedict XVI states that Dionysius Exiguus committed an error.

According to Jewish sources
Similarities between the Yeshu mentioned in some rabbinic literature and the Christian Jesus have led some researchers to speculate that the former is a reference to the latter (see for example Jesus in the Talmud). This opinion is disputed however, as Yeshu also can mean "may his name and memory be blotted out", probably used as a damnatio memoriae to censor certain names. It is claimed in the Talmud that Yeshu was born during the reign of Alexander Jannaeus, who ruled from 103 BC to 76 BC. Furthermore, Sanhedrin 107b and Sotah 47a mention Yeshu taking refuge in Egypt during Alexander's persecution of Pharisees (88-76 BC). Therefore, it can be assumed the Yeshu of the Talmud was born after 103 BC but before 88 BC. Hagigah 2:2 also depicts Yeshu similarly, while also claiming that Yeshu became an apostate during his refuge in Egypt.

The Talmudic claim that Yeshu was born c. 103 – 88 BC is also repeated in the Toledot Yeshu, an 11th-century Jewish text, which implies that this belief was held by at least some Jews at that time. Baring-Gould (page 71) points out that the Wagenseil version of the Toledot Yeshu incorrectly names the Queen as Helene and describes her as the widow of Alexander Jannaeus who died in 76 BC. (her name was in fact Salome Alexandra, and she died in 67 BC). The Yeshu of the Toledot Yeshu clearly refers to Jesus of Nazareth, and there is no possibility that he is another person named Yeshu because the tract was specifically written as a response to the claims of the canonical gospels. It circulated widely in Europe and the Middle East during the Middle Ages as a Jewish response to the Christian account. A 15th-century Yemenite version of the text is titled, or the "Episode of Jesus"—in which Jesus is described as being the son of either Joseph or Pandera—repeats the same claim about the date when Yeshu lived. However, scholarly consensus generally sees the Toledot Yeshu as an unreliable source for the historical Jesus.

Two competing hypotheses for 25 December
Two main hypotheses have been offered as to the choice of the calendar date: 25 December.

Calculation hypothesis
The "Calculation hypothesis", suggests that Christmas was calculated as nine months after a date chosen as Jesus's conception (the Annunciation): 25 March, the Roman date of the spring equinox. The hypothesis was first proposed by French writer Louis Duchesne in 1889. Susan Roll (1995) wrote that the calculation hypothesis is historically the "minority opinion" on the origin of Christmas, but was "taught in graduate liturgy programs as a thoroughly viable hypothesis".

In AD 221, Sextus Julius Africanus named 25 March, the traditional spring equinox, as the day of creation and of Jesus's conception. While this implies a birth in December, Africanus did not offer a birth date for Jesus, and he was not an influential writer at the time. Some early Christians marked Jesus's crucifixion on a date they deemed equivalent to the 14th of Nisan, the day before Passover in the Hebrew calendar. This feast was referred to as the Quartodeciman (Latin for 'fourteenth'). Some early Christian writers equated the 14th of Nisan with the equinox on 25 March, and made the date of his conception or birth the same as that of his death. Duchesne conjectured that Jesus was thought to have been born and died on the same day, so lived a whole number of years, "since symbolic number systems do not permit the imperfection of fractions". However, he admitted that this theory is not supported by any early Christian text.

Adam C. English, professor of religion at Campbell University, has argued for the veracity of 25 December as Jesus's date of birth. The Bible in Luke 1:26 records the annunciation to Mary to be at the time when Elizabeth, mother of John the Baptist, was in her sixth month of pregnancy. English assumes that Zechariah's ministry in the Temple, as described in Luke 1:5–23, took place on Yom Kippur the year before Jesus's birth; he then traces the narrative in the Gospel of Luke through the Annunciation and the birth of John the Baptist to conclude that Jesus was born on 25 December. The earliest evidence for the Feast of the Annunciation (or Incarnation) is from the sixth century. Susan Roll questions whether "ordinary Christians in the third and fourth centuries [were] much interested in calculations with symbolic numbers". Likewise, Gerard Rouwhorst believes it is unlikely that feasts emerged "on the basis of calculations by exegetes and theologians", arguing "For a feast to take root in a community more is needed than a sophisticated computation".

History of religions hypothesis
Theology professor Susan Roll writes: "No liturgical historian... goes so far as to deny that it has any sort of relation with the sun, the winter solstice and the popularity of solar worship in the later Roman Empire." Related to the winter solstice theory, the "History of Religions" hypothesis proposes the Church chose 25 December as Jesus's birthday (dies Natalis Christi) to appropriate the Roman winter solstice festival dies Natalis Solis Invicti ('birthday of the Unconquered Sun'), held on the same date. It honored the sun god Sol Invictus, whose cult was revived by the emperor Aurelian in AD 274. In Rome this yearly festival was celebrated with thirty chariot races. Gary Forsythe, Professor of Ancient History, says: "This celebration would have formed a welcome addition to the seven-day period of the Saturnalia (December 17–23), Rome's most joyous holiday season since Republican times, characterized by parties, banquets, and exchanges of gifts". In AD 362, the emperor Julian wrote in his Hymn to King Helios that the Agon Solis was a festival of the sun held at the end of the Saturnalia in late December.

A Christian treatise attributed to John Chrysostom and dating to the early fourth century AD associates Jesus's birth with the birthday of Sol:

"Our Lord, too, is born in the month of December... the eighth before the calends of January [25 December]... But they [the pagans] call it the 'Birthday of the Unconquered'. Who indeed is so unconquered as Our Lord? Or, if they say that it is the birthday of the Sun, [we may say] He is the Sun of Justice."

The theory is mentioned in an annotation of uncertain date added to a manuscript by 12th-century Syrian bishop Jacob Bar-Salibi. The scribe wrote:

"It was a custom of the Pagans to celebrate on the same 25 December the birthday of the Sun, at which they kindled lights in token of festivity. In these solemnities and revelries, the Christians also took part. Accordingly, when the doctors of the Church perceived that the Christians had a leaning to this festival, they took counsel and resolved that the true Nativity should be solemnised on that day."

In the 17th century, Isaac Newton, who was coincidentally born on 25 December, suggested the date of Christmas was chosen to correspond with the winter solstice. In 1743, German scholar Paul Ernst Jablonski argued the date was chosen to correspond with the Natalis Solis Invicti. The hypothesis was first developed substantially by Hermann Usener, a fellow German scholar, in 1889 and adopted by many scholars thereafter.

Steven Hijmans of the University of Alberta says the idea that the date was chosen to appropriate the pagan festival "has received wide acceptance". He agrees that the Church chose the date because it was the winter solstice, but he argues that "While they were aware that pagans called this day the 'birthday' of Sol Invictus, this did not concern them and it did not play any role in their choice of date for Christmas". Hijmans says: "while the winter solstice on or around December 25 was well established in the Roman imperial calendar, there is no evidence that a celebration of Sol on that day  the celebration of Christmas". Thomas Talley argues that Aurelian instituted the Dies Natalis Solis Invicti partly to give a pagan significance to a date he argues was already important for Christians. The Oxford Companion to Christian Thought remarks that the "calculations hypothesis potentially establishes 25 December as a Christian festival before Aurelian's decree".

According to C. Philipp E. Nothaft, a professor at Trinity College Dublin, though the history of religions hypothesis "is nowadays used as the default explanation for the choice of 25 December as Christ's birthday, few advocates of this theory seem to be aware of how paltry the available evidence actually is."

Day and season
Despite the modern celebration of Christmas in December, neither the Gospel of Luke nor Gospel of Matthew mention a season for Jesus' birth. Scholarly arguments have been made regarding whether shepherds would have been grazing their flock during the winter, with some scholars challenging a winter birth for Jesus, and some defending the idea by citing the mildness of winters in Judea and rabbinic rules regarding sheep near Bethlehem before February.

Adam C. English, professor of religion at Campbell University, argues for the veracity of 25 December as Jesus's date of birth. English assumes that Zechariah's ministry in the Temple, as described in, took place on Yom Kippur the year before Jesus's birth; he then traces Luke's narrative through the Annunciation and the birth of John the Baptist to conclude that the Nativity occurred on 25 December.

Alexander Murray of History Today argues that the celebration of Christmas as the birth day of Jesus is based on a date of a pagan feast rather than historical analysis. Saturnalia, the Roman feast for Saturn, was associated with the winter solstice; Saturnalia was held on 17 December of the Julian calendar and later expanded with festivities only up through 23 December. The holiday was celebrated with a sacrifice at the Temple of Saturn and in the Roman Forum, as well as a public banquet, followed by private gift-giving, continual partying, and a carnival atmosphere that overturned Roman social norms. The Roman festival of Natalis Solis Invicti has also been suggested, since it was celebrated on 25 December and was associated with some prominent emperors. It is likely that such a Christian feast was chosen for Christ's marked contrast and triumph over paganism; indeed, new converts who attempted to introduce pagan elements into the Christian celebrations were sharply rebuked.

Alternatively, 25 December may have been selected owing to its proximity to the winter solstice because of its symbolic theological significance. After the solstice, the days begin to lengthen with longer hours of sunlight, which Christians see as representing the Light of Christ entering the world. This symbolism applies equally to the celebration of the Nativity of Saint John the Baptist on 24 June, near the summer solstice, based on John's remark about Jesus that "He must increase; I must decrease." .

In the 1st and 2nd centuries, the Lord's Day (Sunday) was the earliest Christian celebration and included a number of theological themes. In the 2nd century, the Resurrection of Jesus became a separate feast (now called Easter) and in the same century Epiphany began to be celebrated in the Eastern Churches on 6 January. The festival of the Nativity which later turned into Christmas was a 4th-century feast in the Western Church notably in Rome and North Africa, although it is uncertain exactly where and when it was first celebrated.

The earliest source stating 25 December as the date of birth of Jesus is likely a book by Hippolytus of Rome, written in the early 3rd century. He based his view on the assumption that the conception of Jesus took place at the Spring equinox which Hippolytus placed on 25 March, and then added nine months to calculate the date of birth. That date was then used for the Christmas celebration. 25 March would also roughly be the date of his crucifixion, which ancient Christians would have seen as confirming the date of his birth, since many people of that era held the belief that the great prophets were conceived into the afterlife on the same date they were conceived into the world. Ignacio L. Götz suggests that Jesus could have been born "in the late spring of the year because pregnancies began in the fall after the harvests were in and there was enough money for a wedding feast." John Chrysostom argued for a 25 December date in the late 4th century, basing his argument on the assumption that the offering of incense mentioned in refers to the offering of incense by a high priest on Yom Kippur (early October), and, as above, counting fifteen months forward. However, this was very likely a retrospective justification of a choice already made rather than a genuine attempt to derive the correct birth date. John Chrysostom also writes in his homily "Nativity of our Lord Jesus Christ" ("Εἰς τὸ γενέθλιον τοῦ Σωτῆρος ἡμῶν Ἰησοῦ Χριστοῦ") that the date of 25 December was well known from the beginning among Westerners.

Other sources stating 25 December as the date of Jesus are:
 * Evodius in an epistle reported in part by Nikephoros Kallistos Xanthopoulos in his Ecclesiastical History II, 3
 * Saint Jerome described a commentary by Victorinus of Pettau on papers by Alexander of Jerusalem:
 * We have found, among the papers of Alexander, who was Bishop in Jerusalem, what he transcribed in his own hand from apostolic documents: on the eighth day before the calends of January Our Lord Jesus Christ was born, during the consulate of Sulpicius and Camerinus [sic: Quintus Sulpicius Camerinus was consul in AD 9]
 * Theophilus, bishop of Caesarea, as reported in Historia Ecclesiae Christi (or Centuriae Magdeburgenses, cent. II. chapter VI

Lastly, 25 December might be a reference to the date of the Feast of Dedication, which occurs on 25 Kislev of the Jewish calendar. This would require that early Christians simply translated Kislev directly to December.

Islamic view
The Qur'an, which is the source of Islamic tradition tells the story of Mary and the birth of Jesus (known in Islam as 'Īsā: Messenger of God) most prominently in Chapter 19. According to verse 19:25, during labor Mary was told to shake a palm tree so that ripe dates would fall off. This description, combined with the ripening period of dates places the birth of Jesus somewhere between June and October, with later times being more likely due to dates falling off easily. In the hadith compilation Tuhaf al-Uqul, the sixth imam, Jafar As Sadiq says the following when approached about the birth of Jesus during Christmas: "They have lied. Rather, it was in the middle of June. The day and night become even [equal] in the middle of March". This statement of his does not literally mean it was on 15 June but it is in reference to a day near the spring equinox.