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National Yellow Bat Day

Honor the bravery and contributions of the Army Security Agency on National Yellow Bat Day - a day dedicated to their service and sacrifice.

Wednesday

April 2027

Last updated February 7, 2026 · by the Holiday Calendar Team

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YEARLY DATEApril 21

OBSERVED INUnited States

CATEGORYAnimals

SUBCATEGORYWildlife

INTRO

Introduction

PHOTO

Get ready to honor and pay tribute to the Army Security Agency on April 21, also known as National Yellow Bat Day! This day holds special significance as it marks the activation of one of the most important branches of intelligence for the US Army during the Vietnam War. The 265th airborne division played a crucial role in managing information and providing crucial support during this time. So let's take a moment to celebrate their contributions and show our appreciation for their service. And why not add a touch of fun by wearing something yellow, the color associated with this agency? Let's make this National Yellow Bat Day one to remember!

TIMELINE

National Yellow Bat Day Timeline

Creation of the ASA

The Army Security Agency (ASA) is formed as a branch dealing with signals intelligence, cryptology, and electronic warfare.

Activation of the 265th ASA

The 265th ASA company is activated, focusing on airborne radio direction finding operations during the Vietnam War.

First Mission of Yellow Bat

On April 21, the first ASA mission with the code name "Yellow Bat" takes to the sky, a date now commemorated as National Yellow Bat Day.

End of the ASA

The Army Security Agency is deactivated and its functions are taken over by the Military Intelligence Corps.

National Yellow Bat Day Recognition

The National Day Calendar officially recognizes National Yellow Bat Day, honoring the service and sacrifices of the ASA.

GET INVOLVED

How to Celebrate National Yellow Bat Day

Dress in yellow and bat-themed attire

Get into the spirit of National Yellow Bat Day by dressing up in yellow and bat-themed clothing. This could include yellow shirts, bat-shaped accessories, or even full-on bat costumes!

VISIT

Visit a museum or exhibit about the Army Security Agency

Take a trip to a museum or exhibit that showcases the history and impact of the Army Security Agency. This can be a great way to learn more about the agency and its role in US military intelligence.

HOST

Host a trivia night about the Army Security Agency

Gather some friends together and test your knowledge about the Army Security Agency with a trivia night. You can research and come up with your own questions or use online resources for inspiration.

MAKE

Make yellow bat-themed treats

Get creative in the kitchen and make some yellow bat-themed treats to celebrate the day. This could include yellow cupcakes with bat-shaped icing or bat-shaped cookies decorated with yellow frosting.

DONATE

Donate to a charity that supports veterans

In honor of the Army Security Agency and its contributions, consider making a donation to a charity that supports veterans or active duty military personnel. This is a great way to show your appreciation and give back on National Yellow Bat Day.

WHY THIS DAY MATTERS

Why National Yellow Bat Day is Important

Celebrating patriotism

National Yellow Bat Day is a chance to celebrate our country and show our patriotism. By recognizing and honoring the Army Security Agency, we are also acknowledging the bravery and dedication of all those who have served in our armed forces.

Honoring the Army Security Agency

National Yellow Bat Day is a way to commemorate and honor the important work of the Army Security Agency. This agency played a crucial role in intelligence and information gathering during the Vietnam War, and it's important to recognize their contributions and sacrifices.

Remembering history

National Yellow Bat Day is an opportunity to remember an important part of our nation's history. It allows us to reflect on the past and appreciate the efforts made by the Army Security Agency and other branches of the military during the Vietnam War.