The query centers on the relationship between a specific date, the proper noun "September 11," and the status of a "mail holiday," a compound noun denoting a day of suspended postal services. September 11 is not a federal holiday, and therefore the United States Postal Service (USPS) maintains its normal operational schedule. Mail delivery and all retail post office services are conducted as they would be on any other non-holiday weekday.
The United States federal government officially recognizes a specific list of public holidays, during which non-essential federal offices and services, including the USPS, are closed. These holidays are established by law (5 U.S.C. 6103) and include days such as New Year's Day, Martin Luther King, Jr.'s Birthday, Memorial Day, and Christmas Day. In contrast, September 11 is federally designated as Patriot Day and a National Day of Service and Remembrance. This designation is an observance to honor the individuals who lost their lives in the 2001 terrorist attacks, but it does not carry the legal status of a federal holiday that mandates the closure of government services.
In practical terms, individuals and businesses can expect all postal operations to function without interruption on September 11. This includes the collection of mail from mailboxes, processing at sorting facilities, and delivery to residences and businesses. Similarly, other major private shipping carriers, such as FedEx and UPS, also operate on their standard schedules. While the day is marked by solemn ceremonies and moments of reflection, its status as an observance rather than a federal holiday means it does not affect commercial or governmental activities like mail service.
