October 1, technically, was the due date, but because that fell on a Saturday, a two-day extension was granted.
Of course, if you wish, you can pay the full amount today but if not, the second installment will be due December 1, and you will not get a notice prior to that due date, according to Hall County Tax Commissioner Keith Echols.
Hall Co. Tax Commissioner Keith Echols
http://accesswdun.com/article/2011/10/242432