(avg. read time: 8–15 mins.)
After sifting through all the references, it is time to collate what we have identified as most relevant evidence for determining the time of Jesus’s birth. 1) If our theory is probable about the reasoning behind Augustus’s census work (Luke 2:1), the census could have been anywhere between 7 and 2 BCE. But since Judea was a client kingdom far from Rome, and since Augustus may not have decided to perform such a census until the latter half of this period, we are most likely looking for Jesus’s birth to coincide with the census in 4–2 BCE. Confirmation for this range appears in references to two other rulers. 2) Herod the Great (Matt 2:1–8, 19–21; Luke 1:5) most likely died early (before the Passover) in 1 BCE. While his command to kill those male infants two years old and younger cannot be used with any precision, it still indicates that Jesus was born not long before this, and apparently not long before Herod himself died. 3) John the Baptist (and later Jesus) begins his ministry in the 15th year of Tiberius (Luke 3:1), which is most likely either 28 or 29 CE. 4) Luke says that Jesus was about 30 years old at this time (Luke 3:23). The last two pieces of evidence give us a date of either 3 or 2 BCE. This is consistent with 1) and 2).
What then about the possibility of Jesus being born on December 25? No clear evidence as yet stands against Jesus being born on December 25, 3 BCE. However, it is likely that if Jesus was born in 2 BCE, he would not have been born on December 25. As indicated earlier with the problem of his birth being in 1 BCE, such a birth date would be too close to the events of the final months of Herod’s life to fit the Gospel chronologies. There is not enough time for the forty days to the presentment at the temple (which would have been in February), much less to work in the magi and the flight to Egypt. This does not mean that 2 BCE cannot be the year Jesus was born, but it does mean that we have good reason to think that Jesus was not born on December 25 in 2 BCE.
To see if we can possibly get a date range, we need to look to one last piece of evidence. 5) Now that we have a choice of year between 3 and 2 BCE, we can try applying our 6-year priestly cycle to determine when Zechariah’s order of Abijah may have been serving in the temple, while remembering that 6) Elizabeth conceived 6 months before Mary. That cycle as articulated in List 4 in Part 5 is as follows:
Year 1: Heshvan 15–22 and Iyyar 6–13
Year 2: Tishri 26–Heshvan 4 and Nisan 17–24
Year 3: Tishri 8–15, Adar 29–II Adar 6, and Av 19–26
Year 4: Shevat 10–17 and Av 1–8
Year 5: Teveth 22–29 and Tammuz 13–20
Year 6: Teveth 4–11 and Iyyar 24–Sivan 1
We know the year running from Tishri 1, 2 BCE–Tishri 1 1 BCE was a Sabbatical year, and thus that it would not be intercalated in Judea.1 This means that this year cannot be Year 3 or Year 6 in our proposed cycle. We also know that the rabbis were against intercalating the year following the Sabbatical year, as well, which means that Years 3 or 6 cannot be in Tishri 1, 1 BCE–Tishri 1, 1 CE. We also know that the cycle must take into account the following Sabbatical year of 6/7 CE and the post-Sabbatical year of 7/8 CE to make sure that these years do not fall on intercalary years in the cycle. This will also mean that we must account for a different type of cycle than two consecutive cycles of intercalating once every three years, as in such a scenario a Sabbatical or post-Sabbatical year is guaranteed to fall on an intercalation year. But in such a scenario, represented in the first table, it would be more likely that a post-Sabbatical year would be subject to necessity than a Sabbatical year, given the significance of the Sabbatical year:2
Table 1: Intercalating (Mostly) Every 3 Years, Beginning on a Sabbatical Year
Table 2: Intercalating (Mostly) Every 3 Years, Beginning after a Sabbatical Year
Table 3: Intercalating (Mostly) Every 3 Years, Beginning 3 Years Before a Sabbatical Year
Table 4: Intercalating (Mostly) Every 3 Years, Beginning 4 Years Before a Sabbatical Year
Table 5: Intercalating Alternating Intervals, Beginning on a Sabbatical Year (to avoid intercalating the post-Sabbatical year as often as possible)
Combining 5) and 6) with the other four pieces of evidence, we can see that Zechariah would have been serving late in Tishri 5–Tishri 4 BCE, anytime in Tishri 4–Tishri 3 BCE, or early in Tishri 3–Tishri 2 BCE. We also must remember going forward that our charts of the years begin with Nisan, while the actual priestly cycle would begin in Tishri. This means that only the second service of Year 1 would be included in, say, Tishri 9–Tishri 8 BCE, while the first service of Year 7 (equivalent to the first service of Year 1) would be included in the latter part of, say, Tishri 4 to Tishri 3 BCE. Of these options, is there any scenario in which Jesus could conceivably have been born on December 25?
Scenario 1: Zechariah’s Service Was in 5–4 BCE
In Table 1, Zechariah would be serving in Year 5 in a regular cycle, meaning he would serve in the last week of Teveth in 5 BCE and the middle of Tammuz in 4 BCE. Parker and Dubberstein calculate that the end of Teveth coincided with the end of December in 5 BCE and that the middle of Tammuz would have been the second or third week of June in 4 BCE.3 If we account for up to a 30-day margin of error, that would mean that Zechariah’s service in this time would have been between the end of November–the end of December 5 BCE and the mid-May–mid-June 4 BCE. If John’s conception was within a month after these ranges, his birth would have been between the end of August–the end of October 4 BCE or mid-February–mid-April 3 BCE. Jesus would have then been born roughly between the end of February–end of April 3 BCE or mid-August–mid-October 3 BCE.
In Table 2, Zechariah would be serving in Year 4 in a cycle akin to the beginning of List 3, meaning he would serve in the middle of Shevat and the beginning of Av. Parker and Dubberstein calculate that the middle of Shevat in 5 BCE would correspond to mid-February in 4 BCE and the beginning of Av coincided with the end of July in 4 BCE. If we account for up to a 30-day margin of error, that would mean that Zechariah’s service in this time would have been between mid-January–mid-February 4 BCE and the end of June–end of July 4 BCE. If John’s conception was within a month after these ranges, his birth would have been between mid-October–mid-December 4 BCE or the end of March–the end of May 3 BCE. Jesus would have then been born roughly between mid-April–mid-June 3 BCE or the end of September–end of November 3 BCE.
In Table 3, Zechariah would be serving in Year 2 in a regular cycle, meaning he would serve at the end of Tishri–the beginning of Heshvan 5 BCE and the second half of Nisan 4 BCE. Parker and Dubberstein calculate that the end of Tishri–beginning of Heshvan corresponded to the end of October–beginning of November 5 BCE and the second half of Nisan corresponded to the second half of April 4 BCE. If we account for up to a 30-day margin of error, that would mean that Zechari’s service in this time would have been between the end of September–beginning of November 5 BCE and the second half of March–second half of April 4 BCE. If John’s conception was within a month after these ranges, his birth would have been between the end of June–beginning of September 4 BCE or the second half of December 4 BCE–second half of February 3 BCE. Jesus would have then been born roughly between the end of December 4 BCE–beginning of March 3 BCE or the second half of June 3 BCE–second half of August 3 BCE.
In Table 4, in Year 3, an intercalary year, in a regular cycle (corresponding to Year 9 in the second cycle), Zechariah would serve three times in the first half of Tishri, the end of Adar–the beginning of II Adar, and the second half of Av. Parker and Dubberstein calculate that this part of the first half of Tishri corresponded to mid-October in 5 BCE, the end of Adar–the beginning of II Adar corresponded to the end of March–the beginning of April, and the second half of Av coincided with mid-August in 4 BCE. If we account for up to a 30-day margin of error, that would mean that Zechariah’s service in this time would have been between mid-September–mid-October 5 BCE, the last weeks of February–the beginning of April, and mid-July–mid-August 4 BCE. If John’s conception was within a month after these ranges, his birth would have been between mid-June–mid-August 4 BCE, the last weeks of November 4 BCE–the beginning of January 3 BCE, or mid-April–mid-June 3 BCE. Jesus would have then been born roughly between mid-December 4 BCE–mid-February 3 BCE, the last weeks of May–July 3 BCE, or mid-October–mid-December 3 BCE.
In the case of Table 5, the first period of service would be the same as in Table 1, so all we must figure out is what the second period would be in the case of Year 5 being an intercalary year. The second period of service would have been in mid-Sivan 4 BCE. Parker and Dubberstein calculate that this second period corresponded to mid-June 4 BCE. If we account for up to a 30-day margin of error, that would mean that Zechariah’s service in this time would have been between mid-May–mid-June 4 BCE. If John’s conception was within a month after this range, his birth would have been between mid-February–mid-April 3 BCE. Jesus would have then been born roughly between mid-August–mid-October 3 BCE.
In short, for the purpose of addressing the basic question of this essay: there are two possible ranges in which Jesus could have been born on December 25 if Zechariah served in 5–4 BCE. The first and lower-probability option is represented by the first ministration in Table 3 and the second option is represented by the first ministration in Table 4. However, in both cases the year would be 4 BCE. While not impossible by our chronology, this option is on the lower end of probability. In several other cases, it is perfectly possible for Jesus to have been born in 3 BCE if Zechariah’s service was in 5–4 BCE.
Scenario 2: Zechariah’s Service was in 4–3 BCE
Due to the already extensive repetition in the previous section, and due to the likelihood that the reader understands the reasoning for each piece, I will not be repeating the tables in full here.
Table 2.1: Zechariah’s Service in 4–3 BCE in Different Cycle Schemes
We see once again a couple of scenarios in which it was possible for Jesus to have been born on December 25. The first and third ministrations in Table 3, where 4–3 BCE is an intercalary year, could have possibly preceded a Dec 25 birth in 3 or 2 BCE. Of course, as we have already established, the Dec 25, 2 BCE date is too late to accommodate Herodian and Gospel chronology.
It is also becoming clear that there is no need to consider further possibilities of when Zechariah served, as adding another year would result in every date being unfeasible for Jesus’s birth with Herod still alive. There are thus a limited number of circumstances in which Jesus could have been born on December 25, in two cases leading us to 4 BCE, one to 3 BCE, and one to 2 BCE. Of these options, if this was the day of Jesus’s birth, the best option for the year would be 3 BCE.
How plausible is December 25, 3 BCE? It appears to be as plausible as any other date we could supply for Jesus’s birth. In terms of early Christian claims, it fits comfortably with the chronology provided by Irenaeus, Clement of Alexandria, Tertullian, Origen, at least one work of Eusebius, Sulpicius Severus, and Cassiodorus. It would also fit with the common belief in the early Church noted in Part 5 that Zechariah served in temple during Yom Kippur. While this claim also accreted notions that Zechariah had this encounter in the Holy of Holies (and thus that he was serving as high priest), it nevertheless could be possible that these claims retain a kernel of a historical memory of Zechariah serving during such a time, assuming a particular scenario outlined here is what played out in history.
In terms of Gospel evidence, it fits with Jesus being more than a year old before Herod’s death. It fits comfortably with a likely period in which Augustus is ordering censuses across his Empire and its client states. And if Jesus’s baptism was in 28 CE, it would fit his being about 30 at the time. Specifically, if Jesus was baptized any time in the summer or fall, Jesus would have been under 30, but closer to 30 than any other age. On the less probable meaning of Jesus being just over 30, this scenario would also still obtain in 29 CE.
But as I said before, all we can establish here is possibility and plausibility. There are plenty of circumstances I have outlined in which Jesus’s birth is not on December 25. The dating via Zechariah’s priestly service relies on some theoretical calculations that require a specific, though not implausible, set of circumstances. We do not have independent confirmation that Tishri 4–3 BCE was an intercalary year, because we generally lack such records. If it was not one, the only other recourse to December 25, 3 BCE being the date would be to assume an even larger gap than possibly a month between Zechariah’s service and John’s conception, given one of the other set of circumstances outlined above. But as it stands, December 25, 3 BCE remains a plausible date for the birth of Jesus.
Mahieu, Herod the Great, 45. For the supporting evidence on dating the Sabbatical years, see ibid., 43–45.
The following tables have the intercalary years in bold and the Sabbatical and post-Sabbatical years in italics.
All citations of Parker and Dubberstein from this point forward come from Babylonian Chronology, 45.