For starters, Rosh HaShannah of 3 BCE would have begun at sunset of Monday September 9 of the Julian calendar, had it existed, and ended at nightfall of Tuesday September 10. The equivalent Gregorian dates would be September 22/23.
Although this is an interesting conspiracy theory, it unfortunately does not coincide with either chr-stian birth narrative, which incidentally do not coincide with each other.
In the Matthew birth narrative, Herod the Great was ruler of Judaea during the unknown date and year of the child’s birth. One thing that is a historically proven fact is that Herod the Great ruled Judaea as a Tributary, or Vassal State, of the Roman Empire from 37 BCE until his death on approximately April 1 of 4 BCE.
The Matthew narrative in no way gives us any idea what year the child may have been born, but according to the Matthew story the family was living in Egypt for some unknown amount of time at the time of Herod’s death.
Something that the story does tell us is that at some unknown amount of time after the child’s birth an unspecified number of magoi, which were z-roastrian priests, visited Herod. According to the story Herod questioned the magoi, and carefully calculated the date of the star’s first appearance. Herod then ordered all male children in Bethlehem 2 years of age and younger to be killed.
The story goes on to say that an angel told Joseph to take his family and flee to Egypt to avoid Herod’s decree. It also tells us that they were residing in Egypt at the time of Herod’s death. The only thing we can really determine from this story is that they were living in Egypt for some unknown amount of time at the time of Herod’s death. One thing that is certain is that it would have taken them 30 days to travel from Bethlehem to the nearest inhabitable Egyptian town, by either ox cart or donkey cart. This means that the latest possible date they could have left Bethlehem would have been late February of 4 BCE.
Assuming that there is any fraction of reality involved in this story, the only thing we can determine for certain is that they had been living in Egypt for some unknown amount of time prior to Herod’s death. It could have been days, weeks, months or even years. Therefore, according to the story in Matthew, the very latest possible date for the child’s birth would have been late February of 6 BCE, and the earliest date any time after 37 BCE.
The birth narrative in Luke is a completely different story, taking place at a completely different period of time, with a completely different set of events. However the biggest difference between the two is that Matthew gives us only one constant and everything else are variables, whereas Luke gives us several verifiable constants.
Luke’s story begins by stating that Herod was ruling Judaea, but he does not specify which Herod, but the events of the story actually do verify that it was in fact Archelaus. He also mentions a Priest named Zechariah who was of the division of Abijah. There were a total of 24 divisions of priests. Each division of priests served in the Temple for one week, two times per year; and during the weeks of Pésaḥ, Shavuot and Sukkot for a total of 5 weeks per year. Abijah was the eighth division.
Each week of service began and ended on the Sabbath. Division 1 could begin anywhere between Nisan 1 and Nisan 7 depending upon which date the Sabbath happens to fall that particular year. Therefore Division 8 could begin anywhere between Iyyar 27 and Sivan 4. This makes things rather easy to calculate.
In the year 5 CE Division 8 would have served Sivan 2-16/May 31-June 13 because it includes the week of Shavuot (aka festival of weeks). Therefore Elizabeth became pregnant shortly after June 13 of 5 CE, and would have given birth to John somewhere around March 13 of 6 CE. Because it informs us that Mary became pregnant 6 months after Elizabeth, she would have become pregnant somewhere shortly after December 13 of 5 CE, and given birth somewhere around September 13 of 6 CE. How do these particular dates fall in line with recorded history?
On or about August 21 of 6 CE Herod Archelaus was deposed and banished by the Roman Government, and the territory that he ruled as a Vassal State, which included Judah, Samaria and Edom, was annexed by Rome and became the Roman province of Judaea; and Coponius was appointed as the first Prefect. Shortly thereafter on or about September 7 of 6 CE Publius Sulpicius Quirinius was appointed Governor of the District of Syria, of which the new province of Judaea was a part. Because he was a brand new Governor and because several new provinces had recently been added to the District, it was necessary to conduct a Tax Census, to assess exactly how much tax each citizen was obligated to pay.
The deposing and banishment of Archelaus, the appointment of Coponius as Prefect, the appointment of Quirinius and the Tax Census are all well documented Historical facts. However, because these are well documented historical facts, it is also where the birth story completely falls apart.
According to the story in Matthew, Joseph and Mary lived in Bethlehem until they fled to Egypt, and they did not relocate to Nazareth until they returned and discovered that Archelaus was now ruling Judah. However, according to the story in Luke they lived in Nazareth the entire time and only traveled to Bethlehem for the Tax Census. This is impossible.
Nazareth was in Galilee, which along Peraea were still being ruled by Herod Antipas, and were still Vassal States. A Vassal State is not an official province of Rome and is therefore not taxable by Rome. Instead, a Vassal State pays an annual tribute to Rome. Citizens of Galilee were not subject to the Tax Census ordered by Quirinius. Even if they had been subject to it, they would not have had to travel anywhere. A Tax Assessor would have come to their home to appraise the value of their property, the size of their family and the amount of their income. That is how Tax assessment works. So even though the Tax Census is an absolute historical fact, the events of the birth story are factually impossible. The Roman Government would not have cared at all about anyone’s ancestors, or where they were from. The only thing they were concerned with was the property value of where a person lived right then, the size of their current family and their income.
So according to Matthew he was born no later than February of 6 BCE and according to Luke he was born in mid-late September of 6 CE. Very irreconcilable differences. Not to mention that history itself proves that the events recorded in the chr-stian texts are historically impossible.
It is an archaeologically proven fact that Bethlehem of Judaea was completely uninhabited from the Fourth Century BCE until the late Fourth Century CE. It is also an archaeologically proven fact that Nazareth did not exist until approximately 200 CE. Existing Tax Records verify these archaeological findings.
According to all historical evidence chr-stianity is a vacuum prior to 380 CE, after that it is everywhere. Logic dictates that chr-stianity was invented by Emperor Theodosius I in 380 CE. Chr-stianity only has a history according to chr-stian legend, and that is called hearsay, and would not be admissible as evidence in any Court anywhere on Earth. So attempting to assume a date of birth for the protagonist of the chr-stian story is really no different than trying to assume the birthdate of Pinocchio or Peter Pan.