In addition, the Thursday night show at World Cup of Hockey in Toronto has been outright cancelled.
According to the news release, the postponed concert dates are: St. Louis, MO on 9/20, Chicago, IL on 9/21; and Detroit, MI on 9/24.
The cancellation comes because several band members and some crew members came down with an illness.
They wrote in a statement about how sad they were to postpone and cancel, but the infection that they've been battling got the best of them.
Green Day will not be starting their fall tour as planned.
They're also set to drop its twelfth album, "Revolution Radio", on October 7.
They won't be playing the first three dates of their American tour or a show in Toronto.
"Tickets will be refunded from point of purchase". Each of the tour dates except Toronto will be rescheduled, and tickets for the original dates will be honored for the new concerts.
The band - who are touring in promotion of their upcoming album "Radio Revolution" - hope to be back on the road in time for their show in Columbus, Ohio, on September 26.
Earlier this month, the punk band announced their first tour dates in the United Kingdom in three years.