September 13, 2026, is the 256th day of the year, with 109 days remaining, and it falls on a Sunday, closing out the thirty-seventh week of the year.
With 22 national and international days on the calendar, September 13 is one of the biggest dates in the whole month. National Grandparents Day was made official in 1978 when President Jimmy Carter signed legislation following a campaign by Marian McQuade of West Virginia, and it remains one of September’s most searched-for days. National Scooby-Doo Day celebrates the debut of Scooby-Doo, Where Are You! on this date in 1969, the Hanna-Barbera series that turned mystery-solving cartoons into a cultural phenomenon.
International Chocolate Day coincides with the birthday of Milton S. Hershey, whose innovations helped turn chocolate into an everyday treat. And Uncle Sam Day, first proclaimed in 1989 by President George H. W. Bush, honors Samuel Wilson, the War of 1812 meat supplier whose barrel stamps gave rise to America’s most recognized personification.
National Days on September 13
All national & international days celebrated today
22 celebrations on this day Day 256 of 365 · 109 days left · week 37 · Virgo season · 🌒 waxing crescentNational Grandparents Day
Made official in 1978 when President Jimmy Carter signed legislation following a campaign by Marian McQuade of West Virginia, honoring the bond between grandparents and grandchildren.
National Scooby-Doo Day
Celebrates the debut of Scooby-Doo, Where Are You! on September 13, 1969, the Hanna-Barbera series that turned mystery-solving cartoons into a cultural phenomenon.
International Chocolate Day
Coincides with the birthday of Milton S. Hershey, whose innovations helped turn chocolate from a luxury into an everyday treat across the United States.
Uncle Sam Day
First proclaimed in 1989 by President George H. W. Bush, honoring Samuel Wilson, whose War of 1812 barrel stamps gave rise to America’s most recognized personification.
Here’s every observance celebrated on September 13, 2026.
National & International Days on September 13
Here’s a closer look at the 21 national and international days celebrated on September 13.
9×13 Day
9×13 Day is celebrated every year on September 13, named for the popular 9 inch by 13 inch baking pan size. People mark it by cooking and baking dishes that fit that pan, like casseroles, lasagna, or sheet cake. It started as a fun food related observance in 2017.
Cachaça Day
Cachaça Day (Brazil 🇧🇷) commemorates the legalization of cachaça production in 1661, following the Cachaça Revolt of 1660, when producers resisted Portuguese restrictions aimed at promoting imported liquor. The revolt symbolized Brazil’s struggle for economic independence, and the subsequent recognition of cachaça cemented its role as a cultural and national symbol. Today, cachaça is one of the world’s most consumed spirits and the key ingredient in the caipirinha cocktail. Brazil officially established the day in 2009 through the Brazilian Institute of Cachaça (IBRAC), tying modern celebrations to centuries of history.
🍹 While Brazil celebrates on September 13, an international version of Cachaça Day is also observed on June 12.
International Chocolate Day
International Chocolate Day coincides with the birthday of Milton S. Hershey (1857–1945), founder of the Hershey Chocolate Company, whose innovations helped transform chocolate into an accessible, everyday treat in the United States. The U.S. National Confectioners Association recognizes September 13 as a celebration of chocolate’s long history, cultural significance, and global popularity. While similar holidays exist—such as World Chocolate Day on July 7 and U.S. National Chocolate Day on October 28—this observance connects directly to Hershey’s legacy.
National Bald is Beautiful Day
National Bald is Beautiful Day, created by John Capps of Morehead City, North Carolina, reflects both humor and pride. Capps, who once faced job rejection due to baldness, founded the Bald Headed Men’s Convention more than 50 years ago and used it to promote acceptance and confidence for bald men. The annual September 13 observance encourages people to challenge beauty stereotypes, embrace natural appearances, and celebrate baldness as a source of dignity and individuality.
National Celiac Disease Awareness Day
National Celiac Disease Awareness Day was established by a unanimous U.S. Senate resolution in 2010 to honor Dr. Samuel Gee (1839–1911), born on this date, who first documented the link between diet and celiac disease in 1887. Celiac disease is a serious autoimmune disorder triggered by gluten, causing damage to the small intestine. The day raises public understanding of the condition, emphasizes the importance of early diagnosis, and promotes efforts toward better treatments and a cure.
National Defy Superstition Day
National Defy Superstition Day challenges old beliefs about bad luck and irrational fears. Though its exact origins remain unclear, the holiday gained traction around 2015 as a modern reminder to use reason and critical thinking instead of following baseless superstitions. Falling on September 13—sometimes associated with the unlucky Friday the 13th—it encourages people to break mirrors without worry, walk under ladders without fear, and embrace rational thought over folklore.
National Grandparents Day
National Grandparents Day* (First Sunday after Labor Day) was made official in 1978 when President Jimmy Carter signed legislation following a campaign by Marian McQuade of West Virginia. She envisioned the holiday as a way to honor grandparents, strengthen bonds with grandchildren, and remind younger generations to learn from their elders’ wisdom. The day celebrates family continuity, generational love, and the important role grandparents play in nurturing cultural and family traditions.
National Hug Your Boss Day
National Hug Your Boss Day, observed on the first working day after September 13, was founded in 2008 by the job site TipTopJob.com as a lighthearted way to strengthen workplace relationships. Unlike National Boss’s Day in October, which focuses on formal recognition, this day emphasizes positivity, humor, and team-building through friendly gestures like hugs or appreciation activities.
National Kids Take Over the Kitchen Day
National Kids Take Over the Kitchen Day, created by the Young Chefs Academy, encourages children and teens to step into the kitchen, plan meals, and learn essential cooking skills. The observance highlights how meal preparation teaches math through measuring, literacy through reading recipes, and responsibility through food safety and cleanup. By empowering kids, the day also promotes healthier eating habits and strengthens family bonds through shared mealtime traditions.
National Peanut Day
National Peanut Day honors one of the world’s most popular legumes—despite its name, the peanut is not a nut but part of the bean family. Cultivated for thousands of years in South America, peanuts spread globally after European contact. In the United States, their popularity grew thanks to Dr. George Washington Carver, who promoted peanuts as a sustainable crop and developed more than 300 uses for them. The day also acknowledges peanut allergies, which affect many families, while celebrating the cultural and agricultural importance of peanuts worldwide.
National Ska Day
National Ska Day commemorates the day in 1964* (it was actually Sept. 12, 1964 but the observance now falls on Sept. 13 annually) when Jamaica threw a big concert celebrating ska, the upbeat, off-beat dance music that became the island’s first homegrown pop sound, on its 5th birthday. The date comes from a real 1964 newspaper ad for that event, featuring the genre’s biggest singers, musicians, and rival sound system promoters of the day. It has stuck as the annual date ever since, especially among ska historians and festivals reviving the original occasion.
National Scooby-Doo Day
National Scooby-Doo Day celebrates the debut of Scooby-Doo, Where Are You! on September 13, 1969. The animated series, created by Hanna-Barbera, transformed children’s television by combining humor with mystery-solving and quickly became a cultural phenomenon. Scooby-Doo and his friends—Shaggy, Velma, Daphne, and Fred—have since appeared in numerous spin-offs, films, and reboots. This day honors not only a beloved character but also the enduring influence of storytelling and animation on multiple generations.
National Twilighters Day
National Twilighters Day was founded in 2019 by April Tinnes, Patsy Harrison, Twyla Moore, and Cindy Stapp to celebrate the Twilight series by author Stephenie Meyer. Observed on September 13, Bella Swan’s fictional birthday and Meyer’s real one, the day recognizes the series’ cultural impact since the first book was published in 2005. Celebrations in Forks, Washington—the setting of the saga—attract fans from around the world, highlighting the franchise’s lasting role in popular culture and literature.
Pet Birth Defect Awareness Day
Pet Birth Defect Awareness Day, created in 2014 by David Rogers of the MBJungle Foundation, raises awareness about congenital conditions in pets and the responsibilities of owners. It emphasizes the importance of prevention through ethical breeding, veterinary care, and informed pet adoption. The day also encourages compassion for animals living with birth defects and aims to highlight the human role in shaping pet health outcomes.
Positive Thinking Day
Positive Thinking Day, first observed in 2003, encourages people to focus on optimism, resilience, and the benefits of a hopeful mindset. While the holiday itself is modern, the philosophy of positive thinking draws from earlier traditions like the New Thought movement of the late 19th century, which emphasized the power of constructive attitudes. On this day, people are encouraged to reframe negative thoughts, spread encouragement, and recognize the link between optimism, mental health, and overall well-being.
Programmers Day
Programmers Day, also known as the Day of the Programmer, is celebrated on the 256th day of the year—September 13 in common years and September 12 in leap years. The number 256 is significant in computing, representing the total values possible in one byte (2^8). First established in Russia in 2009, the day honors software developers and programmers whose work underpins modern technology. It is a reminder of how digital innovation shapes nearly every aspect of daily life.
Roald Dahl Day
Roald Dahl Day, launched in 2006 on what would have been the author’s 90th birthday, celebrates the legacy of one of the most influential children’s writers of the 20th century. Known for classics like Charlie and the Chocolate Factory, Matilda, and The BFG, Dahl’s works blend whimsy, wit, and a touch of darkness that captivates readers across generations. Events on this day often include readings, performances, and fundraisers for Roald Dahl’s Marvellous Children’s Charity, supporting seriously ill children.
Snack a Pickle Time
Snack a Pickle Time, also called Snack a Pickle Day, is an informal food holiday observed each year on September 13th that simply encourages people to enjoy pickles as a snack. It’s distinct from the older National Pickle Day, which traces back to 1949 through the National Pickle Packers Association, while this September 13th date comes from social media. Either way, it’s just a fun excuse to eat a pickle, whether on its own or as part of a meal.
Supernatural Day
Supernatural Day commemorates the premiere of the cult TV series Supernatural on September 13, 2005. Declared an official observance in 2016 through a partnership between Warner Bros. and Hot Topic, the day celebrates the show’s enduring popularity and its passionate fan base. In 2018, Austin, Texas, even proclaimed September 13 as Supernatural Day in recognition of its impact. Fans worldwide mark the occasion with watch parties, cosplay, and charity events, showing how the Winchester brothers’ adventures continue to inspire.
Uncle Sam Day
Uncle Sam Day, first proclaimed in 1989 by President George H. W. Bush, honors Samuel Wilson of New York, whose nickname inspired the enduring symbol of the U.S. government. During the War of 1812, Wilson supplied meat to the Army, stamping barrels with “U.S.” for United States property. Soldiers associated the mark with “Uncle Sam” Wilson, their kindly supplier, and the name stuck. Today, Uncle Sam is one of the most recognized personifications of the nation, representing both patriotism and history.
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