National Nonprofit Day is observed annually on August 17 in the United States, to celebrate the contributions of nonprofit organizations and the individuals who work or volunteer for them. Established in 2017 by Sherita J. Herring, the day commemorates the Revenue Act of 1894, which initiated tax exemptions for charitable organizations. The observance encourages people to acknowledge nonprofits by sharing their support on social media using hashtags like #NationalNonprofitDay and #NNDay, donating to or volunteering for causes they care about, and organizing community charity events. Nonprofit organizations vary widely, including charities, labor unions, public schools, and social advocacy groups, and can be categorized as either member-serving or community-serving. While many rely on volunteers, most nonprofits also employ paid staff to manage operations and support their missions.