on the website, it says on Mondays from 9pm-10pm at the overlook pavillion...

my bad, in the spring they had it on the weekends, I guess they changed it up for the summertime.

You've been to Callaway gardens before right? 85 South the whole way...roughly a 1hr 45min drive from ATL. If you go thru the main entrance, at the first intersection, you make that right and it will take you to that pavillion area.