A year and a half before the summer of 586 BCE was the winter of 588/587 BCE. Precisely 2600 years later, taking into account that there was no year zero, is the winter of 2013/2014. In other words, it's a century marker for Asarah b'Tevet.
I wonder if it was as snowy back then. The snow, of course, being one reason I didn't post this on time. :-)