The Dewey Decimal Classification has been in use for over 148 years and continues to be one of the most popular book classification systems in the world, despite efforts to eliminate its use in some libraries. As of 2021, more than 200,000 libraries in over 134 different countries are estimated to still be using this system.

Its popularity is directly related to the fact that this system does an amazing job of keeping books organized and also helps to make those books easier to find within a specific category. That’s why we should all take a few moments to celebrate Dewey Decimal System Day on December 10th and show it some love.

The History of the Dewey Decimal System

Dewey Decimal System Day is observed annually on December 10th because that’s the day when Melvil Dewey was born. Melvil Dewey was an American librarian and library reformer who developed this library classification system in 1873 while he was employed at Amherst College Library.

In 1876, he published “A Classification and Subject Index for Cataloguing and Arranging the Books and Pamphlets of a Library.” He would use this pamphlet to encourage feedback from other librarians.

In 1885, the second edition of the Dewey Decimal System was published. Between this year and 1942, several different editions of this system were released, with modifications and expansions of the system made as deemed necessary.

By the late 1920s, this system was used in approximately 96% of responding public libraries and almost 90% of responding college libraries. In 1993, the first electronic version of this system was created.

Over the past few years, however, the popularity of this system has begun to wane, and some libraries have changed to alternative classification systems. It’s unknown if the use of this system will continue into the future or if it’s destined to become just another footnote.

Interesting Facts About the Dewey Decimal System

Since we’re enjoying Dewey Decimal System Day, we thought it would be interesting to dig up some facts to share with our readers. The following facts are what we’ve come up with, and in all honesty, some of these facts were quite surprising.

• Some booksellers and libraries are moving away from the Dewey Decimal System and are organizing by category or author.
• The DDS section on religion is skewed towards Christianity. Up until 280, Christianity is the only religion covered, and from 290-299 is used to cover the other 4,000 religions in the world.
• In the 1930s, Dorothy Porter of Howard University created a new system to undo the racist way the Dewey Decimal System categorized Black writers.

Observing Dewey Decimal System Day

Observing this holiday is as easy as taking a few moments out of your day to learn more about library classification systems—even if your library uses an alternative to the Dewey Decimal Classification.

You can also take some time to learn more about Melvil Dewey and his efforts to make library browsing an easier experience for people going to the library. While you’re observing this holiday, be sure to use the hashtag #DeweyDecimalSystemDay on social media to spread the word about it.