The march always takes place on May 1 and held on the same stretch of Santa Clara Street. But this year, they'll have company.
"The city decided to schedule Viva Calle on May Day, on the May Day route, inexplicably," said May Day committee member Shaunn Cartwright.
Viva Calle, San Jose's open streets event, will overlap them in both time and place. That means the route will be closed to traffic and there will be bicyclists, food trucks, and live music competing for attention with the march.
"It is hard to plan this event and feel respected in the community when you have the city planning an entire other event on top of it," said another organizer Mak Aruta Konefa.
City officials said they didn't realize the scheduling snafu until it was too late.
They tried to explain that to the May Day coalition.
"I understand exactly where they're coming from. We have apologized to the best of our abilities in that it was a logistical oversight and that they're not on a calendar," said Ed Solis of San Jose's Parks, Recreation and Neighborhood Services Department.
City officials said they've tried to make it right, paying for pedicabs to shuttle march participants, as well as a stage and sound system.
"In the end I think it will be great for us to collaborate forces. We're not trying to outshine or take the spotlight away from the group but help amplify their message," said Solis.
There will also be police to help make sure the events don't impede each other. Still May Day organizers say that doesn't alleviate their concerns.
"We don't know what other people's political leanings will be, and we have to be really diligent on ensuring the safety of the May day participants," said Aruta Konefa.
City officials said the overlap won't happen again.
Organizers can't believe it happened in the first place.
"We really don't understand this cultural amnesia," said Cartwright.
Viva Calle will run from 10 a.m. until 3 p.m. The May Day March starts at about noon.
Organizers said attendees can expect detours and big crowds on Sunday.