Herring Day (Sillens Dag) is observed in Sweden every June 6, coinciding with Swedish National Day. This holiday, established in 2008 in Klädesholmen, celebrates herring, a staple food that has been significant in Swedish cuisine and culture since at least 3000 BC. Events in Klädesholmen include a market with vendors selling herring and other foods, children's activities, cooking workshops, and demonstrations by the Swedish Sea Rescue Society, which benefits from fundraising activities during the celebration. Iconic herring dishes such as pickled herring, herring salad, and surströmming highlight the culinary importance of this fish. Attendees can also visit the local Herring Museum and participate in herring tastings, with proceeds supporting the Sea Rescue Society.