AFTER A LITTLE RESEARCH:
Assyrians record total solar eclipse event on clay tablet.
This eclipse actually occurred on July 17, 709 BCE. Essentially this eclipse works for either year, 763 BCE or 709 BCE, so the reference is non-specific.
March 19, 721 BCE
First recorded lunar eclipse, seen in Babylon.
Interesting. I'll look this up and comment further. Otherwise, the 1st of Nebuchadnezzar II did not begin until 547 BCE. 721 BCE would still have been the Assyrian Period.
Addendum: I looked this up and found this reference for this eclipse:
Quote: "There is also the testimony of an eclipse, to this date; for Sargon mentions “the eclipse visible over Haran,” which by the Almagest is shown to have been March 19, 721 B. C. 25[Page 341] “Records of the Past.” Old Series, Vol. vii, p. 27. "
I didn't even bother to check this out further at first, since lunar eclipses are quite common and the month is not mentioned. Finding another lunar eclipse 54 years later thus would not be any different than the 709 BC vs 763 BCE eclipses. But just to demonstrate how this works, apparaently lunar eclipses also follow a similar predictable pattern of eclipses that occur every 54 years and 1 month apart over the same location. Assuming that for this period of time the timeline is 54 years off, we just checked for a lunar eclipse over Babylon in 667 BCE (721 - 54 = 667 BCE). Guess what? Another total lunar eclipse occurs over Babylon on April 21, 667 BCE, exactly 54 years and 1 month later. So if that text is a contemporary text, it works just as well for both timelines as does the Assyrian eponym eclipse which we can date to either 763 or 709 BCE. So glad I looked this up. That was pretty simple to dismiss and document.
April 6, 648 BCE
Earliest documented total solar eclipse; chronicled by Greeks.
I looked this up and, indeed, amazing to me, there was another total solar eclipse seen by Smyrna 54 years and 1 month later on May 9, 594 (648 - 54 = 594 BC). But this is a nonspecific reference of just an eclipse he saw. This is a poet who didn't say which year he experienced the eclipse. So we'd have to look at his entire history to see how many solar eclipses he experienced during his lifetime. But of critical note, Wikipedia says: "Mimnermus (Greek: Μίμνερμος Mímnermos) was a Greek elegiac poet from either Colophon or Smyrna in Ionia, who flourished about 630–600 BC." The immediate problem here is that the 648 BC eclipse he allegedly reflects on occurs some 18 years before the time assigned to him beginning in 630 BC. So the eclipse doesn't occur during the time he would have been an active adult. 648 BC is an eclipse almost 20 years earlier. So this reference doesn't work and who knows how many total eclipses over Smyra occurred in a 30-year period some 54 years later? So again, totally inconclusive.
I'm glad you mentioned these references because they don't check out.
May 28, 585 BCE
Thales Miletus predicts solar eclipse; Persian-Lydian battle ends.
This eclipse is stated to have occurred during the reign of Nabonidus, not Nebuchadnezzar II and is not a predictable eclipse. This eclipse event actually happened in year 2 of Nabonidus, in early 478 BCE. This is a misdated eclipse. Thank you for the other references!!! 585 BCE for Thales is definitely wrong.
Further comment: In this case, we looked for a possible eclipse event match for the Bible timeline that dates the 1st of Cyrus to 455 BCE based upon several criteria. Essentially, the reign of Nabonidus is calculated based on Cyrus beginning his 20-year rule over Persia Minor in the 6th year of Nabonidus. Cyrus becomes king over all Medo-Persia (Persia Major) 20 years later in 455 BCE, thus the beginning of his 20-year reign would have occurred in 575 BCE (455 + 20 = 575 BCE). If that was the sixth of Nabonidus, then Nabonidus would have begun to rule in 480 BCE. But Nabonidus was only on the throne for 3 years, thus from the Spring of 480 BCE to the Spring of 477 BCE.
The reference in Herodotus to this eclipse event was an eclipse over Ionia predicted by Thales during the reign of Nabonidus. 585 BCE fails that initial reference since 585 BCE is otherwise the 21st year of Nebuchadnezzar II. The historical context of this Media-Lydia peace agreement is during the time of Nabonidus not Nebuchadnezzar, 105 years earlier! So 585 BCE is out, out, out before we even begin.
Our concern, since apparently he was connected with a predictable eclipse was whether or not there was a predictable eclipse over Ionia during the 3-year period of the reign of Nabonidus between 480-477 BCE? No problem looking that up. When we did, we did find a total eclipse going directly through Ionia on February 17, 478 BCE! Indeed, it was part of a predictable solar eclipse pattern since a matched eclipse occurs exactly 54 years and 1 month earlier over Egypt on January 15, 532 BCE. The question is, whether or not Thales had reasonable access to the records of this Egyptian eclipse. That answer is: Yes! Thales studied astronomy at Egypt for 7 years. So what apparently happened was during his studies he found out about this predicted eclipse event that was going to happen over his own country of Ionia. So he went there and "warned" them about this eclipse that was to happen in a specific month and year. When it happened, he became famous. Plus this is the time when Nabonidus was actually ruling and he is the king said to have mediated the Lydian-Mede peace agreement.
Just for some context, Cyrus conquered the Medes in the 6th year of Nabonidus. he did this with the aid of Darius the Mede with whom he later conquered Babylon 13 years later after a conflict with the Lydians because of this peace agreement. Darius the Mede was 62 when he conquered Babylon per the Bible (Daniel 31: "And Darius the Mede received the kingdom, he was about 62 years old.) That means Darius the Mede wasn't even born until year 22 of Nebuchadnezzar II. So that eclipse event doesn't work at all historically.
So this predicted eclipse event by Thales works better with the 455 BCE chronology because (1) the 478 BCE eclipse was indeed a predictable eclipse based on a matched eclipse over Egypt where Thales studied astronomy, and (2) It does indeed occur during the 3-year active rule of Nabonidus before his son, Belshazzar became his co-ruler and became the active king while Nabonidus went to Borsippa to devote himself to his moon god, Sin.
So come up with something else. This is all inconclusive and disproven and all these events are exchangeable or better matched to the true timeline. But thanks for noting these events. It was fun to do a background check on these references that have you convinced.