One option would be July 23-Aug. 8. That is exactly one year from the now-postponed July 24-Aug. 9 dates.
Bach says the exact dates is a question for the Tokyo organizing committee and an International Olympic Committee panel overseeing the preparations.
Swimming and track have their biennial world championships scheduled to start in July or August 2021.
Bach cites the World Health Organization saying in the last couple of hours that Africa has to prepare for the worst.
The IOC has been advised by the WHO, which said Monday the pandemic is accelerating.
Bach says the original health issue for hosting the Tokyo Olympics was could Japan offer a safe welcome" and the IOC was confident it could.