The term functions as a proper noun phrase. The core component, "Patriot Day," is a specific American observance, which is geographically qualified by the noun adjunct "UK." The phrase thus frames an inquiry into whether a British equivalent exists, rather than naming an established event. Determining its function as a noun phrase is essential, as it defines the subject as a specific entity or concept to be explained.
The United States observes Patriot Day on September 11th to commemorate the victims of the 2001 terrorist attacks. The United Kingdom does not have an officially designated day with this name or a direct counterpart. The most significant day of national remembrance in the UK is Remembrance Sunday, the second Sunday in November, which honors armed forces personnel who have died in the line of duty since World War I. While the UK holds memorials for victims of specific terrorist events, such as the July 7, 2005 London bombings, these are typically localized or anniversary-specific and have not been consolidated into a single, recurring national day analogous to the American one.
The query for a "Patriot Day" in the UK highlights a difference in how national tragedies are memorialized. The UK's primary framework for collective mourning and patriotism is historically rooted in military conflict, embodied by Remembrance Sunday. The term in question, therefore, represents a conceptual gap; it refers to an idea for which no formal tradition currently exists within the British national calendar. Its application is analytical, used to compare national commemorative practices.