SunDay is a global day of action on September 21st, 2025, celebrating the unstoppable rise of clean energy. We’ll come together to showcase the power of the sun and wind, the energy sources that can power our world without pollution. Join the Aspen One team, professional skiers and snowboarders, Holy Cross Energy, local politicians, environmental nonprofits, and community members to celebrate Aspen's commitment to clean energy and support this growing national movement.