The proper noun "Patriot Day" refers to the annual observance in the United States held on September 11. This date commemorates the individuals who lost their lives as a result of the terrorist attacks on September 11, 2001.
The observance was established by presidential proclamation and a joint resolution of the U.S. Congress shortly after the events. Officially designated as "Patriot Day and National Day of Service and Remembrance," the day is marked by flying the U.S. flag at half-staff at all federal buildings and individual homes. A nationwide moment of silence is typically observed at 8:46 a.m. Eastern Daylight Time, corresponding to the time of the first impact. It is distinct from Patriots' Day, a regional holiday in April celebrating the American Revolutionary War.
In practice, while it is a national observance, it is not a federal holiday, meaning schools and businesses generally remain open. The day's purpose is twofold: to serve as a solemn memorial for the victims, first responders, and their families, and to encourage Americans to engage in acts of service and charity as a positive tribute to their memory. This dual focus on remembrance and community action defines the modern interpretation of the observance.