Astronomers, who are one of the groups very interested in Late Babylonia, use astronomical year numbering with a year 0 to make the math easier, but Amelie Kurt

Astronomers, who are one of the groups very interested in Late Babylonia, use astronomical year numbering with a year 0 to make the math easier, but Amelie Kurt gives the date of the fall of Babylon as October 539 BC https://en.wikipedia.org/wiki/Astronomical_year_numbering https://en.wikipedia.org/wiki/Astronomical_year_numbering