The query seeks a specific temporal noun phrase in response to the interrogative adverb "when." The answer is the fixed date of November 11th. Veterans Day is observed annually on this date in the United States.
The historical significance of November 11th is tied to the armistice that ended World War I, effective at the 11th hour on the 11th day of the 11th month in 1918. Originally established as Armistice Day in 1919 and designated a national holiday in 1938, the U.S. Congress amended the holiday in 1954 to honor veterans of all American wars, renaming it Veterans Day. The Uniform Monday Holiday Act of 1968 briefly moved the observance to the fourth Monday in October, but due to the date's profound historical importance, legislation was passed in 1975 to return the official annual observance to November 11th, a change that took effect in 1978.
As a federal holiday, the observance remains on November 11th irrespective of the day of the week. For purposes of pay and leave for federal employees, if the date falls on a Saturday, the preceding Friday is the designated holiday; if it falls on a Sunday, the following Monday is observed. The day honors all individuals who have served in the U.S. Armed Forces, distinguishing its purpose from that of Memorial Day, which specifically honors military personnel who died in service.
