GIS day is a worldwide event that celebrates the technology of Geographic Information Systems (GIS). Ralph Nader inspired GIS Day as a day for geography awareness.
But it was actually the National Geographic Society, Association of American Geographers (AAG) and Esri, who really put the day into action on November 19, 1999. More specifically, it was the National Geographic Society who organized Geography Awareness Week each November in 1987. Since then within that week of geo-literacy, GIS Day typically occurs. Each year, we celebrate GIS Day in November as part of Geography Awareness Week. GIS Day started in 1999 as an educational event for GIS users to showcase their projects that have real-world applications.
This is not just an event. It's a global movement. This day brings universities, government agencies, schools, nonprofits, and GIS professionals together to build knowledge of GIS in their communities and create understanding about the world we live in.