If your calculations are based on scripture alone, why are they given in BC dates?
The timeline of scripture is based on creation, from the beginning.
Because 7 key dates of historical events are given in the usual chronology. 7 significant events of history coincided with 7 jubilees of Israel. Events are "lightning", news about these events are "thunder", the interpretation of these events in the keys of the Bible are "voices of thunder".
1.
20th jubilee - the coincidence of Nehemiah's words about the need to return the lands to the Jews with the law of the jubilee year, dates back to 443 BC.
2.
30th jubilee - the decree of the Apostolic Council in Jerusalem on the liberation of the Gentiles from the Mosaic law, 48 AD.
3.
37th jubilee - Decrees of Theodosius 389-392, the ban on paganism and the forced introduction of Christianity, the death of the Church.
4.
40th jubilee - Emperor Justinian builds the largest church, Hagia Sophia, "Solomon, I have surpassed you!", entombs the Body of Christ in the stone buildings of the official religion, 537.
5.
60th jubilee - Reformation: Luther published his 95 Theses in 1517, Zwingli began his sermons in 1519. This marked the disintegration of the body of the Church into many denominations.
6.
66th jubilee - A charismatic leader tried to conquer Russia: Napoleon's invasion. Napoleon can serve as a prototype of the Antichrist: he was loved by the people, Christians, and occupied a place in their hearts that should have belonged to Jesus Christ. Napoleon's invasion of Russia: 1812.
7.
67th jubilee - The end of serfdom in Russia (reform of Tsar Alexander II), liberation from slavery in the USA (beginning of the civil war). 1861. We see how the ideas of the Bible gradually gained strength and began to be embodied in increasingly large-scale historical phenomena.
So, the "voices of the seven thunders":
1. Return of the land to the Jews.
2. Freedom from the law to the Gentiles.
3. Death of the Church.
4. Burial of the Church.
5. Disintegration of the Church.
6. Collapse of the Antichrist.
7. Freedom for all people.
That's it in short.
The entire sequence of jubilees begins with the introduction of the law on the jubilee year, from the moment of crossing the Jordan, according to Leviticus 25. According to confirmed coincidences with the "lightning" of events, this sequence began in 1423 BC.
The periodicity of jubilees is 49 years (not 50, as some think):
1st - in the 50th year, 2nd - in the 99th year, 3rd - in the 148th year, 4th - in the 197th year, etc.
The same periodicity of jubilees is given in the Book of Jubilees, only there the jubilees are calculated from the creation of Adam until the crossing of the Jordan. There they counted 50 jubilees. If we add up both of them, then the jubilee of 2008 should be the 120th from Adam. But this does not correspond to the law of Moses, because the law says that the counting of the Sabbath years begins after the crossing of the Jordan.
Israel's 70th jubilee came on September 29, 2008, and was marked by a historic record fall of 777 points in the Dow Jones index, which occurred on Rosh Hashanah.