National Yellow Bat Day

National Yellow Bat Day is observed annually on April 21. This military-themed holiday honors the history and contributions of the 265th Army Security Agency (ASA) Company, an airborne unit that provided critical intelligence support during the Vietnam War. The day is named after the unit’s distinctive insignia—a black bat set against a yellow moon—which symbolizes the secretive, nocturnal nature of their surveillance and communications missions.

See also: National Vietnam War Veterans Day, National Former Prisoner of War Recognition Day, Air Force Reserve Birthday

History of National Yellow Bat Day

The date April 21 commemorates the activation of the 265th Army Security Agency Company (Airborne) at Fort Campbell, Kentucky, in 1967. As a subordinate unit of the 101st Airborne Division, these soldiers were specialists in signals intelligence, tasked with intercepting and analyzing enemy communications. Because their work was highly classified, the soldiers operated under the cover name “Radio Research Units” to mask their true purpose from the public and enemy forces. In late 1967, the unit deployed to Vietnam, where they played a vital role in providing tactical intelligence to battlefield commanders.

The holiday was officially established in 2016 by Doug Bonnot, a veteran of the 265th Radio Research Company and author of the memoir The Sentinel and the Shooter. For decades, the efforts of the ASA were kept out of the spotlight due to the sensitive nature of their electronic warfare and countermeasure operations. Bonnot created the day to ensure that the sacrifices and technical achievements of these “silent warriors” were recognized by the general public. The yellow bat symbol, which members originally painted on their equipment and vehicles for identification in the field, remains the primary icon of the unit’s legacy.

Why is National Yellow Bat Day important?

This day is important because it sheds light on a previously invisible chapter of American military history. The intelligence gathered by the 265th ASA was instrumental in detecting enemy movements and uncovering the plans for major campaigns, such as the Tet Offensive in 1968. By recognizing this unit, the holiday honors the technical skill and bravery required to operate sophisticated equipment in high-risk combat zones. It serves as a reminder that victory and troop safety often depend on the quiet work of analysts and interceptors who work “through the night.”

Beyond its historical value, National Yellow Bat Day highlights the evolution of modern military intelligence. The ASA was the predecessor to the United States Army Intelligence and Security Command (INSCOM), and the techniques developed by these airborne units laid the groundwork for today’s signal processing and cyber security fields. Celebrating this day allows veterans and their families to share stories that were once restricted by security oaths, fostering a deeper community understanding of the complexities of the Vietnam conflict.

• The unit provided early warnings that helped protect thousands of ground troops.
• The bat insignia represents the stealth and precision of nighttime operations.
• Members were trained in rare languages and advanced cryptology.
• The holiday recognizes the transition from traditional signal units to modern intelligence.
• It honors the commitment to the unit motto, “Through the Night.”

How to Celebrate National Yellow Bat Day

One of the most effective ways to celebrate is by researching the history of the Army Security Agency and the specific missions of the 265th Radio Research Company. Reading memoirs like The Sentinel and the Shooter provides a firsthand perspective on what life was like for intelligence soldiers during the Vietnam era. Many people use the day to visit military museums or the Vietnam Veterans Memorial to pay respects to those who served in specialized support roles. If you know a veteran who served in the ASA, taking the time to listen to their experiences is a meaningful way to honor the spirit of the day.

You can also celebrate by sharing the story of the “Yellow Bats” on social media to increase public awareness of this unique military insignia. Many enthusiasts participate by learning about the technology used in 1960s radio research, such as direction-finding equipment and secure communications systems. Supporting veteran organizations that assist those from the 101st Airborne Division is another practical way to give back. By focusing on the “silent” side of military service, participants help ensure that these specialized contributions are never forgotten.

• Read historical accounts of the 265th RRC’s role in the Tet Offensive.
• Share an image of the yellow bat insignia with the hashtag #NationalYellowBatDay.
• Visit a local veterans’ center to learn about military intelligence history.
• Watch a documentary about signals intelligence during the Cold War era.
• Thank a signals intelligence veteran for their dedicated and quiet service.

National Yellow Bat Day Dates Table