September 11 is not a federal holiday in the United States. While it is a day of solemn national observance, it does not carry the legal designation of a federal holiday, which would entail the closure of non-essential federal government offices, the postal service, and most banking institutions.
The date is officially designated as Patriot Day, a National Day of Service and Remembrance. This status was established by a joint resolution of the U.S. Congress and signed into law by President George W. Bush on December 18, 2001. A later resolution in 2009 designated it as a National Day of Service and Remembrance. An observance, unlike a federal holiday, does not typically include a paid day off for the general workforce; businesses, schools, and government agencies largely operate on a normal schedule.
In practice, Patriot Day is observed with memorial ceremonies, moments of silence, and special tributes to the victims and first responders of the 2001 terrorist attacks. The President issues a proclamation each year calling for the flag of the United States to be flown at half-staff on all government buildings and individual American homes. The day is intended to be a time for reflection, remembrance, and engagement in charitable and community service activities rather than a day of leisure.