When was Jesus born?

Answer:

The day of Jesus' birth gives rise to endless speculations. Instead of picking a day based on some obscure philosophical argument, let's list out the markers that we do know.

Working from the Reign of Herod the Great

"Now after Jesus was born in Bethlehem of Judea in the days of Herod the king" (Matthew 2:1).

Josephus states that Herod was named king during the 184th Olympiad. Olympiads run on a four-year cycle. The 184th Olympiad ran from July 1, 44 BC to June 30, 40 BC. [Josephus, Antiquities, 14.389]. While Herod was named king, he had to conquer his own kingdom, which took place during 185th Olympiad [Josephus, Antiquities, 14.487-488, and Jewish Wars, 1.343].

Other statements by Josephus would put the start of Herod's reign in 38 BC.

• The Battle of Actium (September 2, 31 BC) was Herod's seventh year [Josephus, Antiquities, 15.121].
• Caesar was in Syria (the spring of 20 BC) was Herod's eighteenth year [Josephus, Antiquities, 15.354].

Herod died between a lunar eclipse and before the Passover during his 37th year [Josephus, Antiquities, 17.167,213, and Jewish Wars, 2.10]. This is typically dated as 4 BC because there was a partial lunar eclipse on March 13, 4 BC and the Passover was on April 11 that year. However, there was a full lunar eclipse on January 10, 1 BC and the Passover that year was 89 days later.

Herod was visited by magi concerning the birth of Jesus. Herod ascertained the exact time the magi had seen the star (Matthew 2:7) and later issued an order to kill all boys two years old and younger in an attempt to kill Jesus (Matthew 2:16). Assuming that Herod padded his order around Jesus' age, that would place Jesus' birth around 3 BC to 2 BC. We also note that Jesus is a child and not an infant when the Magi visited (Matthew 2:8-9,13).

Working Backward from Jesus' Baptism

"Now in the fifteenth year of the reign of Tiberius Caesar, when Pontius Pilate was governor of Judea, and Herod was tetrarch of Galilee, and his brother Philip was tetrarch of the region of Ituraea and Trachonitis, and Lysanias was tetrarch of Abilene, in the high priesthood of Annas and Caiaphas, the word of God came to John, the son of Zacharias, in the wilderness" (Luke 3:1-2).

"When He began His ministry, Jesus Himself was about thirty years of age" (Luke 3:23).

Tiberius was appointed as emperor by the Roman Senate on September 17, 14 AD. Like most countries in this era, a king's first year of reign was counted as the calendar year in which he assumed office so Tiberius' fifteenth year was the year 29 AD.  Roman coins also support that Tiberius' first year was 14 AD. This would make Jesus' birth somewhere around the year 1 BC if we assume that Jesus was baptized the same year that John the Baptist began preaching.

If we assume that "about thirty years of age" can allow up to a year variance, Then Jesus was born somewhere between 2 BC and 1 AD.

Time of Year

We are also told that Zacharias, John the Baptist's father, served in the Abijah division (Luke 1:5). It was during his week of service that he was told he would have a son. It was shortly after he returned home that his wife became pregnant (Luke 1:23-24). Mary was told that she would have a child in the sixth month of Elizabeth's pregnancy (Luke 1:26) and she became pregnant immediately thereafter.

Each priestly order served two one-week periods at the temple and Abijah was the eighth order of 24 orders (I Chronicles 24:4-6,10). Thus, it would serve on the eighth and thirty-second service periods. The weeks of major feasts were times all the priests gathered and were not counted as part of the rotation. It is believed that the rotations started in the spring, in the first month of the year. Thus, the division of Abijah would have served a week in late May or early June and a second week in late November or early December.

If it was the first rotation, then Jesus would be born in early September. If it was the second rotation, then Jesus would be born in early March.

We know that it was during the warmer months since the shepherds were staying with their flocks in the fields at night (Luke 2:8). If the fields refer to the farm fields, then the various grains were harvested from late-March for early grains like barley to May for mid-season grains like wheat to July for late-season crops like flax and millet. After everything was gathered the shepherds brought in their flocks to eat the stubble. Come mid-October, the rainy season begins and the sheep are usually kept in pens, especially at night.

"In the springtime there is an abundance of green pasture, and usually the sheep are allowed to graze near to the village where the shepherd's home is located. After the grain is reaped, and the poor have had an opportunity to glean what is left for them, then the shepherd brings in his flock, and the sheep feed on certain fresh growths, or dried blades, or an occasional ear of grain that the reapers may have left, or was overlooked by the gleaners. When this source of food is exhausted then the pasture is sought in other places" [Manners and Customs of Bible Lands].

This makes the early September birth more likely since the shepherds would not be in the fields in early March.