The subject of the query, "Veterans Day," is a proper noun. The central point of an article addressing this topic is to define this noun by its specific, fixed date. Veterans Day is observed annually on November 11th in the United States, not in the month of May. This federal holiday is dedicated to honoring all individuals who have served in the U.S. Armed Forces.
The date of November 11th holds significant historical importance. It commemorates the armistice signed between the Allied nations and Germany, which marked the end of major hostilities in World War I. The ceasefire took effect on the eleventh hour of the eleventh day of the eleventh month in 1918. Originally known as Armistice Day, the holiday was renamed Veterans Day in 1954 to honor veterans of all wars. The query's inclusion of "May" likely stems from a common confusion with a different U.S. military holiday, Memorial Day, which is observed on the last Monday of May.
The distinction between these two holidays is crucial. Veterans Day on November 11th celebrates the service of all military veterans, living or deceased. In contrast, Memorial Day in May is a solemn occasion specifically for remembering and honoring the military personnel who have died in the line of duty. Therefore, the date is a fundamental attribute that distinguishes the proper noun "Veterans Day" and its purpose from "Memorial Day."