Tomorrowland is optimistic in 2021, as the Belgian government has plans to reopen fully by September 1.
Per local news sources, the government has announced that large outdoor events will be allowed up to 75,000 people starting on August 13. Tomorrowland welcomes approximately 400,000 attendees to Boom, Belgium each year over two weekends, or up to 70,000 people each day.
Under the new rules, attendees will be required to present proof of vaccination or test negative for COVID-19 on site. Organizers are confident they can create a safe event by implementing these practices upon entry. 
Tomorrowland recently revealed to Billboard:
We are very happy to receive this news, but we will wait for the conditions and rules before we will communicate about the organization of the festival. We are very positive, and we look forward to organizing a festival [at the] end of August.
As it stands, Tomorrowland is scheduled to take place over August 27 – 29 and September 3 – 5.
Meanwhile, Tomorrowland’s Around The World digital festival is scheduled for July 16 & 17.
Source: Billboard
