Dewey Decimal System Day

Next celebratedThursday, December 10, 2026

Don't miss out on celebrating Dewey Decimal System Day - explore the world of books and knowledge with a library tour or an online book club!

See how to celebrate

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Last updated February 7, 2026 · by the Holiday Calendar TeamHave an update or spot an error?

YEARLY DATEDecember 10

OBSERVED INUnited States

CATEGORYSchool

SUBCATEGORYLiteracy

INTRO

Introduction

It's time to celebrate the Dewey Decimal System on December 10th – a day dedicated to honoring one of the most important library classification systems in the world! The Dewey Decimal System is an organizational tool used to classify books into ten broad categories that make it easier for librarians, teachers and students alike to quickly find the material they need. It was first developed by Melvil Dewey in 1876 and has since become an invaluable part of libraries all over the world. This day is not only a great way to recognize its importance, but also a good reminder to take advantage of all those resources our libraries have to offer!

TIMELINE

Dewey Decimal System Day Timeline

Dewey Decimal System Invention

Melvil Dewey invents the Dewey Decimal Classification system to organize books and other materials in libraries.

Dewey Decimals Copyrighted

Melvil Dewey copyrights the decimal classification system, which later becomes known as the Dewey Decimal System.

OCLC Ownership

OCLC Online Computer Library Center, a nonprofit library cooperative, acquires the rights to the Dewey Decimal System.

Library of Congress Adopts Dewey

The Library of Congress begins using the Dewey Decimal System for its Children's collection.

23rd Edition Released

The 23rd edition of the Dewey Decimal Classification is published by OCLC.

GET INVOLVED

How to Celebrate Dewey Decimal System Day

Organize your library

Take some time and use the Dewey Decimal System to organize your home library. This will make it easier for you to find books when you need them.

VISIT

Visit the library

Head to your local library and explore the shelves. Learn more about the Dewey Decimal System and how it is used in libraries around the world.

CREATE

Create a book display

Design a book display based on the Dewey Decimal System. Choose books from each category and arrange them in order using the DDS.

Go on a scavenger hunt

Hide books around your house and have family and friends search for them using the Dewey Decimal System as their guide.

START

Start a book club

Organize a book club based on the Dewey Decimal System categories. Each month, members can read from one of the 10 categories.

WHY THIS DAY MATTERS

Why Dewey Decimal System Day is Important

It Improves Accessibility

By organizing libraries according to the Dewey Decimal System, accessibility for all types of individuals is improved. People with low vision or physical disabilities can more easily locate books on the correct shelves due to their familiarity with the organization scheme. The same goes for people who are unfamiliar with the Dewey system – because it’s laid out in an orderly fashion, even first time visitors can quickly and accurately find what they need.

It Helps Librarians Make Informed Decisions

The Dewey Decimal System helps librarians organize and find books more quickly, which allows them to make better decisions about what materials should go in the library and where they should be placed. With this system, it's easier for librarians to ensure that patrons have access to the latest titles and niche topics as well as older, classic books.

It Keeps Library Shelves Organized

The Dewey Decimal System makes it easy to keep library shelves organized by placing books into logical categories. This helps library visitors easily find what they're looking for instead of wasting time trying to search through a disorganized shelf of books!

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