Before starting to count, let's read some verses related
to the matter which are part of Jewish History as recorded
in the Bible:

2 King 24:
8 Jehoiachin was eighteen years old when he began to reign,
and he reigned in Jerusalem three months. ...

2 King 24:
11 And Nebuchadnezzar king of Babylon came against the city,
and his servants did besiege it.

2 King 24:
15 And he carried away Jehoiachin to Babylon, and the king's
mother, and the king's wives, and his officers, and the mighty
of the land, those carried he into captivity from Jerusalem
to Babylon.

2 King 24:
17 And the king of Babylon made Mattaniah his father's brother
king in his stead, and changed his name to Zedekiah.
18 Zedekiah was twenty and one years old when he began to reign,
and he reigned eleven years in Jerusalem. ...

2 Chronicle 36:
11 Zedekiah was one and twenty years old when he began to reign,
and reigned eleven years in Jerusalem.
12 And he did that which was evil in the sight of the Lord his
God, and humbled not himself before Jeremiah the prophet
speaking from the mouth of the Lord.
13 And he also rebelled against king Nebuchadnezzar, who had
made him swear by God: but he stiffened his neck, and hardened
his heart from turning unto the Lord God of Israel.

2 Kings 25:1
And it came to pass in the ninth year of his reign, in the
tenth month, in the tenth day of the month, that Nebuchadnezzar
king of Babylon came, he, and all his host, against Jerusalem,
and pitched against it; and they built forts against it
round about.

Jeremiah 37:
5 Then Pharaoh's army was come forth out of Egypt: and when the
Chaldeans that besieged Jerusalem heard tidings of them, they
departed from Jerusalem.

The background of the story is set, we are now at the moment in
time when Nebuchadnezzar left the siege of Jerusalem and went
to fight the Egyptian Army. After defeating the Egyptians,
Nebuchadnezzar returned and resumed the siege of Jerusalem.

For the exact Year, read this Wikipedia Article:
https://en.wikipedia.org/wiki/Zedekiah

The date when Nebuchadnezzar defeated the Army of Pharaoh is
recorded in the old Testament:

Ezekiel 30:
20 And it came to pass in the eleventh year, in the first month,
in the seventh day of the month, that the word of the Lord came
unto me, saying,
21 Son of man, I have broken the arm of Pharaoh king of Egypt;
and, lo, it shall not be bound up to be healed, to put a roller
to bind it, to make it strong to hold the sword.

The eleventh year of the Captivity in Babylon that started at
the end of the reign of Jehoiachin, or the eleventh year of the
reign of the king of Judah Zedekiah, the 7th Day of Nissan of
the Jewish year 3174: this day is March 25th, 587 BC. Link to
Jewish date converter is pasted below:

https://www.floridajewish.com/jewish_date_converter.php

Using the Ezekiel date of March 25th, 587 BC and going forward
239,760 Days (666 years x 360 days Biblical Year), if falls on
August 28th, 70 AD. Link to Date Duration Calculator is pasted
below:

https://keisan.casio.com/exec/system/1247118517

The Temple was destroyed on August 2nd, 70 AD, and based on Ezekiel
30:20, on the date August 28th, 70AD, Jerusalem had fallen. The number
666 in the Book of Revelation is the exact number of biblical years
from when Jerusalem was besieged by Nebuchadnezzar in 587 BC to its
fall in 70 AD.

In his book "Wars of Jews" the Jewish historian Flavius Josephus
wrote:

"AND thus was Jerusalem taken, in the second year of the reign of
Vespasian, on the eighth day of the month Gorpeius [Elul]."

https://www.biblestudytools.com/history/flavius-josephus/war-of-the-jews/book-6/chapter-10.html

Using the Jewish Calendar Converter, the eight day of the month
of Elul 70AD is August 31st, 70 AD.

https://www.floridajewish.com/jewish_date_converter.php

As you have previously read above, after counting 239,760 Days
(666 Biblical year) starting from the Date of Ezekiel 30:20
of March 25th, 587 BC, we calculated that the date of the fall
of Jerusalem was August 28th, 70 AD.

The Jewish Generation that witnessed the Crucifixion of Christ
was totally unware of the soon approaching 666 years deadline
that started the Day Nebuchadnezzar laid siege of Jerusalem
in March 25th, 587 BC.

Related studies on Brighteon:

I beheld another beast coming up out of the earth (Revelation 13:11)
https://www.brighteon.com/e18fa598-e987-4528-be8c-dcb788106f42

Seven Trumpets and Seven Vials (Revelation Chapters 8, 9, 10, 11 and 16)
https://www.brighteon.com/b5a4dec9-6e64-4d30-a7c3-08b253852070

Ye were marked in Him with a Seal
https://www.brighteon.com/e5109860-c06f-474c-bc57-2ff1fb9ae031

Computer Chip or Spiritual Mark of the Beast
https://www.brighteon.com/8cdda8b9-d6fc-4b50-9b01-1960fbfef6ec