1. Battle of Actium

The “Battle of Actium” took place 2 September 31 BC -click-. According to Josephus that was during the seventh year of Herod’s 37 year long reign.
31BC + 30 years reign left = 1 BC.

2. At this time it was that the fight happened at Actium, between Octavius Caesar and Antony, in the seventh year of the reign of Herod

Josephus, Antiquities 15.5.2

1. … for the battle at Actium was now expected, which fell into the hundred eighty and seventh olympiad, where Caesar and Antony were to fight for the supreme power of the world

Josephus, Antiquities 15.5.1

An olympiad is a span of four years. So while it’s accuracy isn’t very great, it can be used as a way of verification of more accurate sources.

The 187th olympiad was between 32-28BC -click-. 31BC falls within that range.

2. Christ - Augustus - Cleopatra

Let us see, moreover, how in the forty-first year of the empire of Augustus, when he has been reigning for xx and viii years after the death of Cleopatra, the Christ is born. (And the same Augustus survived, after Christ is born, xv years;

• Jesus was born when Augustus was emperor for 41 years
• ??? Augustus ruled 40 years…
• Jesus was born 28 year after Cleopatra died.
• 30BC+28=2BC    Click
• Augustus died 15 years after the birth of Jesus,
• 14AD-15=2BC

Tertullian Click

Because of how the calendar worked it’s 3/2BC (part of each)

3. Miracle of the lot - 3BC

A random choosing of the "lot" which was cast on the Day of Atonement (Yom Kippur). The lot chosen determined which of two goats would be "for the Lord" and which goat would be the "Azazel" or "scapegoat." During the two hundred years before 30 CE, when the High Priest picked one of two stones, again this selection was governed by chance, and each year the priest would select a black stone as often as a white stone. But for forty years in a row, beginning in 30 CE, the High Priest always picked the black stone! The odds against this happening are: ½*½ repeated 40 times is 1 in 1,099,511,627,776

John 11:51 Now this he said not of himself: but, being high priest that year, he prophesied that Jesus should die for the nation;

The Temple was destroyed in 70AD - 40 stones - 33 (age Jesus) = 3BC

70-40-33= -3, subtract 1 year because there is no year zero, 4BC.

The first stone was drawn on the Atonement Day before Jesus died. So we shouldn’t add stone, so we subtract one year less, 3BC

4. Ruling over Galilee

And seeing that Hyrcanus was of a slow and slothful temper, he made Phasaelus, his eldest son, governor of Jerusalem, and of the places that were about it, but committed Galilee to Herod, his next son, who was then a very young man, for he was but fifteen*** years of age

Jewish Antiquities, 14.9.2

***= footnote

Those who will carefully observe the several occasional numbers and chronological characters in the life and death of this Herod, and of his children, hereafter noted, will see that twenty-five years, and not fifteen, must for certain have been here Josephus's own number for the age of Herod, when he was made governor of Galilee. See ch. 23. sect. 5, and ch. 24. sect. 7; and particularly Antiq. B. XVII. ch. 8. sect. 1, where about fortyfour years afterwards Herod dies an old man at about seventy.

So Herod received Galilee at the age of 25 and died at the age of 70.

The consensus is that Herod started ruling Galilee in 47BC.

47BC+70-25 = 2BC

That puts Herod’s death in 2/1BC