What most forget is, that every 7th year was a leap year and had the extra-month of AdarII added to harmonize again the lunar and the solar calender. So it plainly had 390 days, not 360 as the previous 6. So one could argue that 7times taken a day for a year could mean 2550 years! That would bring us to the fall of 1944 counted from 607 BC.
But many agree that Jerusalem fell in 586/587. If we now apply this rule, we end up in 1964.
Philippus