Book your advertising space in the Pro D Day Flyer. Advertising in the City of Prince George's Pro-D Day Flyer is a great opportunity to promote your organization. Prior to each Non-Instructional Day (NID)/Professional Development Day, or spring and summer break in School District #57, the City of Prince George coordinates a flyer showcasing local programs and activities offered to youth. The flyer is an excellent resource for parents, educators, and youth to learn about what activities are available and where. It is also a fantastic venue for local businesses and organizations to market themselves and their NID/School Break programs.