it depends on where you're coming from, but The driving distance between Ontario, California to Atlanta, Georgia is 2,143 mi - about 1 day 7 hours. The direct distance between Ontario, CA and Atlanta, GA is 1899 miles (3055 km).
The driving distance between Seattle, WA and Ontario, CA is 1171 miles. The driving time would be approximately 18 hours if driving non-stop in good conditions. (The driving time does not take into consideration conditions such as weather, road work and rush hour traffic in urban areas.)