Screenshot from official Smash Mouth Facebook page.
California rock band Smash Mouth posted a June 1 tour date at Northwestern on their official Facebook page Friday, which coincides with this year's 41st Dillo Day from Mayfest. They are perhaps best known for their 1999 smash hit "All Star" on the album Astro Lounge, though the band has since released five more albums, the last in 2012.
Mayfest has not acknowledged the leak.
"I cannot comment on that at the moment," Promotions Co-Chair Bri Hightower said.
Julie Kliegman contributed reporting.
Editor's Note: An earlier version of this story stated that this year would be the 40th Dillo Day, when in actuality it is the 41st.