Where the World Gathers to Celebrate Every Day


National Exascale Day - October 18


On October 18 (1018), National Exascale Day celebrates the scientists and researchers who make breakthrough discoveries in medicine, materials sciences, energy and beyond with the help of some of the fastest supercomputers in the world.

We like to say that National Exascale Day celebrates those who keep asking what if, why not, and what’s next — with the advanced technology to attain the answers.

This era in technology will have a profound impact on nearly every aspect of our daily lives. It will impact everything from healthcare and manufacturing to understanding new energy sources and the origins of the universe. Exascale is defined as a quintillion computations per second. For perspective, if all 7.7 billion people on earth each completed one calculation per second, it would take over 4 years. An exascale computer can complete a quintillion computations in 1 second.

So what, you may ask?

The “so what” is that when science discovers and innovates in less time, it realizes good outcomes sooner. More people survive cancer. Populations deplete fewer natural resources from the earth. More people have healthy food on their tables. And so on.

HOW TO OBSERVE #NationalExascaleDay

Celebrate the geeks, gurus, and geniuses who keep asking the big questions and are changing the world! To get you started, here are a few ideas:

  • Hug a scientist.
  • Encourage your teams to recognize the great work of a colleague, researcher or anyone who is using advanced computing to change the world.
  • Tell the world via your organization’s website, blog, and media channels how your org views the impacts of Exascale computing on the future.
  • Take a scientist or science teacher for lunch.
  • Celebrate with your teams – ice cream social, picnic lunch, or special recognition ceremony.
  • Keep science alive in your schools by sponsoring a science fair.

Use #NationalExascaleDay to share on social media. Keep reading to learn even more!

We’ve included a bit more information below for you curious-er types.

Fun Factoids
  • Exascale computing means a computing system that can perform at least one exaflops ― or one quintillion (a billion billion) calculations per second.
  • It would take 40,000 years for one quintillion gallons of water to spill over Niagara Falls.
  • The Milky Way galaxy is 1 quintillion kilometers wide.
  • The human brain contains 100 billion neurons – to reach one quintillion would require 10,000 people!
  • Exascale computers will be roughly a million times more powerful than the average laptop we use every day.
A Historical View into the Next Inflection Point

The advent of the Internet allowed business and industry to collect data like never before. Fast forward, data growth continues to drive organizations of all sizes to data-intensive computing and digital transformation. In response, AI, analytics, IoT, simulations, and modeling workloads are all converging into one business-critical workflow – a workflow that must operate at an extreme scale and in real-time.

So, data growth, converging workloads, and the imperative for digital transformation mean organizations are asking completely new questions. And they need new capabilities to answer those questions. Exascale computing completely rethinks how technology and people come together to answer today’s biggest questions ― and even bigger ones tomorrow.

What Makes Now an Exascale Era™?

Exascale is more than a speed milestone or a system size. Exascale is new workloads brought on by new questions intersecting with new compute capabilities to create a major technological shift.



CRAY, a Hewlett Packard Enterprise company, founded National Exascale Day in 2019 to celebrate the people who keep asking, “what if, why not, and what’s next?” — with the advanced technology to attain the answers. The day also celebrates a new era of supercomputing that will enable breakthroughs in disciplines benefitting all of humankind.

The Registrar at National Day Calendar® proclaimed National Exascale Day to be observed on October 18th, annually.

International Legging Day - October 18


Get geared up for International Legging Day every October 18th. Although it’s a year-round staple, when temps drop in the fall, it’s officially legging season!

Once a necessity providing an added layer of warmth, the legging is now an iconic style combining comfort and fashion. Leggings truly set a trend in the 1950s and ‘60s as a standard wardrobe piece and workout essential.

Over time, breathable materials, textures, designs, and prints ushered in the undeniable era of leggings. Now, modern-day leggings are feats of engineering designed to enhance your workout. While they continue to be a gym essential, legging styles are now so versatile that they’re widely acceptable to wear as pants. In a wide range of looks, comfortable leggings offer something for everyone.

As the popularity of athleisure skyrockets, so too does the mass appeal of the legging. Clearly, this comfortable, curve-hugging style hasn’t just revolutionized what we wear to the gym—it’s revolutionized what we wear everywhere! The versatile legging has sparked a global revolution that encourages women to embrace comfort and stay active.


Put your best legging forward! Proudly wear your favorite pair and go shopping for more. Consider this your chance to break the dress code—whether it’s at the office or that five-star restaurant you’re dining at tonight. After all, feeling comfortable is what the day’s really all about. Share your favorite looks and styles by using #LeggingDay on social media on October 18th.



Fabletics founded International Legging Day in 2019 to celebrate the year-round style staple during the official legging season.

The Registrar at National Day Calendar® proclaimed International Legging Day to be observed on October 18th, annually.

National Chocolate Cupcake Day - October 18


National Chocolate Cupcake Day on October 18th annually celebrates the sweetness of small chocolate cakes. With a dollop of frosting, one sweet serving satisfying chocolate and dessert lovers!

Cupcakes have also been known to be called:

  • Fairy Cakes
  • Patty Cakes
  • Cup Cakes (different from Cupcakes (one-word))

Cupcakes can be traced back to 1796 when a recipe notation of “a cake to be baked in small cups” was written in American Cookery, by Amelia Simmons. The earliest known documentation of the term cupcake was in 1828 in Seventy-five Receipts for Pastry, Cakes, and Sweetmeats in Eliza Leslie’s Receipts cookbook.

Bakers initially baked their cupcakes in heavy pottery cups. Today, some still use individual ramekins, small coffee mugs, large teacups, or other small ovenproof pottery-type dishes for baking their cupcakes.

Chocolate cupcakes come in a variety of flavors, too. Of course, there’s always the standard chocolate cupcake. But why stop there on a holiday?

  • Chocolate caramel cupcakes satisfy that extra cry for sweetness.
  • Peanut butter chocolate cupcakes are the snackers delight.
  • Get devilishly good cupcakes with Devil’s Food.
  • Cool things off a bit with chocolate mint recipes, too.
  • And you can’t forget chocolate orange cupcakes. Citrus brightens the flavor of any chocolate recipe.

HOW TO OBSERVE #ChocolateCupcakeDay

Celebrate by trying one of the following tempting recipes while watching an episode of the Food Network reality-based competition show, Cupcake Wars. Remember to invite friends or family over to share. That’s how we like to #CelebrateEveryDay!

Cream Cheese Chocolate Cupcakes
Chocolate Fudge Cupcakes with Peanut Butter Frosting
Super Easy, Super Moist Chocolate Cupcakes
Chocolate Cream Filled Chocolate Cupcakes
Dark Chocolate Cupcakes

Use #ChocolateCupcakeDay to post on social media.


National Day Calendar® continues researching the origins of this sweet cake holiday.



Annually, National No Beard Day on October 18th celebrates the cleanshaven among us. The smoother the face, the bigger the celebration!

Whether you have had your beard for years or it is relatively new for you, this is the day to shave it off and go smooth. Perhaps your partner doesn’t like your beard, or you just haven’t shaved it off for years. No Beard Day is the day to see what you look like without it.

Achieving a close, kissable shave is a lost art that faded with a generation who had the first color televisions installed. Consider investing in the tools your grandfather or possibly your great-grandfather used – either a safety razor or a straight razor will give you the closest shave along with a natural bristled shaving brush and shaving soap.  More care and time may be required, but the results are well worth the effort.

HOW TO OBSERVE #NationalNoBeardDay

Shave and post before and after photos on social media using #NationalNoBeardDay.


National Day Calendar® continues researching the origins of this fashionable holiday. However, next month is No Shave November and since we are halfway through October, indications suggest we start there.

NATIONAL MAMMOGRAPHY DAY – Third Friday in October


Every year on the third Friday in October, National Mammography Day joins in National Breast Cancer Awareness Month.

This day serves as a reminder to all women that the best defense is early detection. A mammogram can often detect a problem before there is any outward physical sign. 

Cancer is the second leading cause of death in the United States according to the CDC. The CDC statistics also report that breast cancer is the most common form of cancer diagnosed among women. Screenings and breast exams are a part of the early detection process. 

When you schedule an annual appointment with your physician, make sure a breast exam is completed, too. Tell your doctor about any changes. If you or your doctor notices any signs, the doctor can order tests, including a sonogram or mammogram.

Finally, a preventative mammogram is the last line of defense. Today’s mammograms offer more vivid detail of the breast tissue. Baseline mammograms are provided around the age of 35 unless family history indicates sooner. The baseline mammogram provides a comparison view for your physician should something develop later down the line. Women age 40 and over are recommended to receive yearly preventative mammograms.

HOW TO OBSERVE #NationalMammographyDay

Visit with your doctor and set up a mammogram and use #NationalMammographyDay to post on social media.


President Bill Clinton proclaimed this National Day in 1993.

On Deck for

National Days

International Days

  • World Pediatric Bone and Joint Day

National Weeks



Recipe of the Day

Basic Truffle Recipe
Prep:  1 hour
Total Prep:  1 hour
Serves 60


1 8 ounce package cream cheese, softened
3 cups confectioners’ sugar, sifted
3 cups semisweet chocolate chips, melted
1 1/2 teaspoons vanilla (may substitute orange, almond, maple, or coffee liqueur)
various toppings (chopped nuts, shredded coconut, sprinkles, cocoa, shaved chocolate)


Beat cream cheese in a large bowl until smooth.

Add the confectioner’s sugar one cup at a time until well blended.

Stir in chocolate and vanilla until well incorporated.

(If using a liqueur flavoring, divide the mixture into thirds and add 1 tablespoon of the preferred liqueur to each prepared mixture.)

Chill for 1 hour.

Shape into 1 inch balls. Roll in your favorite toppings.

About National Day Calendar

National Day Calendar® is the authoritative source for fun, unusual and unique National Days! Since our humble beginnings on National Popcorn Day in 2013, we now track nearly 1,500 National Days, National Weeks and National Months. In addition, our research team continues to uncover the origins of existing National Days as well as discover new, exciting days for everyone to celebrate.

There’s a celebration for everyone. While National Road Trip Day satisfies the itch to wander, many pet days let us share our love of animals. National 3-D Day and National Astronaut Day honor the advancement of technology, too. Every food day you can imagine (National Avocado Day, for example), will keep you celebrating, also!

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Our Ambassador Program is another way #CelebrateEveryDay®! Whether you become an ambassador or follow one of the savvy ambassadors, their fun videos and posts will keep you prepared for every holiday.