Day of AI is a free, hands-on curriculum of lessons and activities designed to introduce K-12 students to artificial intelligence (AI) and how it shapes their lives. The Day of AI curriculum was developed by a team of researchers at MIT RAISE, and designed to be taught by educators with little or no technology background. These resources are free, Creative Commons-licensed, and made to be accessible to students of all backgrounds and abilities. Activities are organized by age group (elementary, middle school, and high school) and can be run in 30-minute to 1-hour time blocks. Teachers who register for Day of AI get access to the curriculum and lesson plans as well as optional free professional development training on the materials with our collaborator i2 Learning, with a certificate of completion that may be used for PD credits.