GIS Day is a grassroots event that formalizes the practice of geographic information systems (GIS) users and vendors of opening their doors to schools, businesses, and the general public to showcase real-world applications of this important technology. The event is principally sponsored by the National Geographic Society, the Association of American Geographers, University Consortium for Geographic Information Science, the United States Geological Survey, The Library of Congress, Sun Microsystems, Hewlett–Packard, and ESRI.
GIS Day is part of the National Geographic Society's exciting new initiative, Geography Action, which is a year-long initiative encompassing key educational achievements such as GIS Day and Geography Awareness Week. Each year this initiative will have a different focus. The theme for 2005-2006 is "Migration: The Human Journey." In addition to events such as GIS Day and Geography Awareness Week, there will also be many worldwide activities supporting geography action, with their goal being to engage people in learning and caring about geography.