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MonSep 9

International Sudoku Day – September 9, 2024

International Sudoku Day takes place, of course, on September 9 (9/9). Sudoku enthusiasts will no doubt notice the date’s symbolism. The goal of the Sudoku game is to fill a 9×9 grid so that each column, row, and 3×3 sub-grid contains all the digits from 1 to 9. So nine-nine is the natural choice for the day of celebration. It’s time to get your brain into gear because although today is most definitely a cause for celebration, some hardcore logical thinking will be required.

History of International Sudoku Day

In 1892, the French newspaper “La Siècle” printed a game that was akin to Sudoku in that each row and column had to contain all the designated numbers, but unlike Sudoku, it involved numerals higher than 9 and engaged solvers’ mathematical skills, not their logic center. In the ensuing years, other French papers picked up on the trend with similar games, but none were strictly identical to Sudoku, and those games’ popularity waned around the time that World War I was starting.

Flash forward to 1979. Circumstantial evidence points to Indiana architect Howard Garns publishing a puzzle of his own invention (at that time named “Number Place”) in “Dell Magazine” that would become the game we now know as Sudoku. Garns, however, passed away without seeing his brainchild become an international sensation. In the meantime, the game set Japan’s puzzle industry on fire, gaining the name Sudoku for the first time, along with a fan base of millions of devoted players. In 1997, Hong Kong judge Wayne Gould invented a computer program that could come up with unique Sudoku puzzles. He pitched the game as a daily puzzle feature to newspapers in the U.K., and soon Sudoku was known around the world.

Today, Sudoku is readily available on smartphone apps and widely printed in papers and magazines. It’s the subject of multiple documentaries and game shows, and even spawned an award-nominated original tune by songwriter Peter Levy. We think it’s safe to say Sudoku isn’t going anywhere any time soon.

In 2013 The World Puzzle Federation made September 9 the official International Sudoku Day and we’ve been celebrating it ever since.

International Sudoku Day timeline

Worth donating to the pledge drive for…

British TV station “Channel 4” begins to include a daily Sudoku puzzle in its Teletext and the program guide “Radio Times” initiates a weekly, 16x16 grid, “Super Sudoku.”

Breaking” the internet

A Sudoku website that published Peter Levy’s song on the topic (“I know these numbers only go to nine / But the skill required to finish one line / Is sometimes more than worth my struggling through…”) has to take it down because the online demand is too great for their servers.

Not impartial to the game

A million-dollar drug trial in Australia is scrapped when it’s discovered that five of the twelve jurors were playing Sudoku instead of listening to the evidence.

A truly worldwide phenomenon

The World Puzzle Federation designates September 9 to be the ongoing annual date of International Sudoku Day and begins holding multi-round online competitions in the category.

International Sudoku Day FAQs

Can I play Sudoku for free?

Yes, absolutely. A simple online search of “free sudoku games” will generate a list of millions of results.

When is International Sudoku Day?

September 9

Who came up with International Sudoku Day?

The World Puzzle Federation established International Sudoku Day.


  1. Solve some Sudoku puzzles

    There’s no better way to observe International Sudoku Day than to solve some Sudoku puzzles! You can do as many or as few as you want, but challenge yourself.

  2. Buy some new puzzle books

    Out of puzzles to solve? Make International Sudoku Day the day you replenish your supply. If you’re a Sudoku connoisseur, hunt around for the most challenging puzzle book you can find. If you're a newbie, there are plenty of entry-level books for you. Either way, get a new book and solve those puzzles like there’s no tomorrow.

  3. Challenge a friend to play head-to-head

    Sudoku doesn’t have to be a one-person activity. Take the challenge to the next level by competing against your friends. Whoever solves the puzzle fastest, wins. You can all participate at the same time, or create brackets to narrow it down to the best puzzle-solver. The winner gets bragging rights and now you’ve emulated the spirit of the World Puzzle Championship, right in your living room!


  1. New York, of course

    Dell Publishing Company was founded in 1921 by New York-born George T. Delacorte, Jr. with the goal of entertaining readers who were sick of the often-ostentatious reading material of the time, an attitude on Delacorte’s part that also led him to erect statues of “Alice in Wonderland,” “The Tempest,” and “Romeo and Juliet” in his native city.

  2. Signs of true distinction

    Dell subsidiary “Asimov’s Science Fiction Magazine” has won the prestigious Locus Award 63 times.

  3. What exactly is “super”?

    In 1979, astrologer Richard Nolle’s definition of a supermoon (a full moon that coincides or nearly coincides with perigee [its point in orbit closest to the earth]) was first coined in “Dell Horoscope” magazine.

  4. Within range of the commuter train

    Dell Magazines’ current parent company, Penny Publications, is headquartered in Norwalk, Connecticut, the hometown of both conductor Vince Mendoza and baseball player Mo Vaughn.

  5. A pen name and a character name

    The “Ellery Queen” of Dell parent Penny Press’ “Ellery Queen Mystery Magazine” was the pseudonym of the two mystery writers Frederic Dannay and Manfred B. Lee, who co-wrote novels like “The Roman Hat Mystery” under the name.


  1. Puzzles are fun!

    Some of us love visual puzzles and prefer word searches. Others love word games and go gaga for crossword puzzles. But if you love numbers, math, and logic, Sudoku is a puzzle that's right up your alley.

  2. We love a good challenge

    It’s fun to be challenged, and Sudoku is excellent at making us think in tough new ways. There are varying degrees of difficulty to match your skills with the game that's right for you. Yes, it can be frustrating sometimes (if you throw your Sudoku book at the wall, just don’t hit a glass picture frame) — but there’s no judgment from fellow Sudoku lovers like us!

  3. It keeps our minds sharp

    Actively participating in things that exercise our brains, especially those that involve math, is a good way to keep our minds sharp. Sudoku can increase focus and concentration as well as alleviate depression. Studies also suggest that puzzles and word games help prevent Alzheimer’s disease and dementia. Who knew Sudoku could be so good for your health?

International Sudoku Day dates

2024September 9Monday
2025September 9Tuesday
2026September 9Wednesday
2027September 9Thursday
2028September 9Saturday

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