Atlanta and New York share the same timezone year-round. When it's 12:00 PM in New York, it's also 12:00 PM in Atlanta. Both cities observe DST on the same schedule.
Both cities use Eastern Time (EST/EDT, UTC-5/-4). Georgia is one of the 17 US states in the Eastern timezone.
Any time works! Business hours are identical. The 2-hour flight makes Atlanta-NYC one of the busiest domestic routes in the US.
Atlanta is home to Coca-Cola, Delta Airlines, and CNN headquarters. The world's busiest airport, Hartsfield-Jackson, handles significant traffic to/from New York.