What is free day?

As an AI language model, I do not have information about specific events or promotions that offer free days. However, please note that free days or freebies are often offered by businesses or organizations as a way to attract customers or provide a perk to loyal clients. These free days may include free admission to museums, parks or attractions, free meals, free classes, or other types of free services or products. It is always a good idea to check with the specific business or organization for details on their free day promotions.