Gwinnett County Tax Assessor notices did go out on April 5th as evidenced by 28 assessment notices I have been sent. The appeal period in Georgia is 45 days in all counties and that makes the appeal deadline in Gwinnett May 20th. This is the last day that your property tax appeal can be postmarked or hand delivered.
I have value changes on approximately 14% of the notices that I have received. Two values decreased, two increased, and 24 had no change in value. No change in assessment isn't necessarily a blessing, especially if your value has remained unchanged for several years and it has not been appealed. In 2012 we appealed many values in Gwinnett County that hadn't changed since the start of the Great Recession. We were able to get most of these reduced.