Grammatically, the term "sep 11 federal holiday" functions as a noun phrase. The head word is the noun "holiday," which is modified by "federal" and "sep 11," both acting as adjectives to specify the type and date of the holiday. Factually, however, September 11 is not a federal holiday in the United States; it is a national day of observance known as Patriot Day.
A federal holiday is one of the eleven days designated by U.S. law (5 U.S.C. 6103) on which non-essential federal government offices are closed and federal employees are paid for the day off. In contrast, Patriot Day and National Day of Service and Remembrance was established by law to be observed on September 11 of each year. This designation calls for the President to issue an annual proclamation, for U.S. flags to be flown at half-staff, and for a moment of silence to be observed at 8:46 a.m. Eastern Daylight Time.
The distinction is significant. While a federal holiday typically involves closures and a day of leisure, an observance like Patriot Day is intended to encourage active commemoration, solemn reflection, and participation in community service. The term in question, therefore, represents a common misconception, conflating a day of profound national remembrance with the legal and practical status of an official public holiday.
