IMSA has chosen to swap two races on the 2020 schedule for the IMSA WeatherTech SportsCar Championship, and some of their support series.
The 6 hours race at Watkins Glen will be moved to Michelin Raceway Road Atlanta, but still on 6 September, and still the same duration.
The Lime Rock race one week later, will be moved to Charlotte Motor Speedway, where the GT cars will race on the ROVAL, which is the infield of the oval.
That is all down to the COVID-19 situation, where the area around New York still have quite a few cases, and the local authorities are running to different regulations, than other states do.
IMSA also informs, that they keep an eye on the evolvment of the COVID-19 situation, and the rest of the 2020 schedule is provisional.