May 20 National Days

May 20 is the 140th day of the year (141st in leap years) in the Gregorian calendar, leaving 225 days until the end of the year. Today’s observances range from scientific milestones and culinary traditions to social causes and pop culture celebrations.

National Days on May 20th — May 20th National Days

A few observances, such as World Autoimmune Arthritis Day and International Red Sneakers Day, were founded in recent years with specific missions, while others like Clinical Trials Day and World Metrology Day mark major historical milestones. All today’s celebrations are fixed-date observances that return every year on May 20.

Here’s a full overview of the 16 national and international days observed on May 20.

National and International Days on May 20

Clinical Trials Day: Honors the first documented clinical trial conducted by British naval surgeon James Lind in 1747, which helped prove that citrus fruits could prevent scurvy. The modern observance was initiated in 2005 by the European Clinical Research Infrastructures Network (ECRIN), and later promoted by the Association of Clinical Research Professionals (ACRP) starting in 2014. The day recognizes the essential role of clinical research in advancing medicine and acknowledges the ongoing work of researchers, participants, and healthcare professionals worldwide.

International Academic Freedom Day: Established in 2024 by Academics for Academic Freedom (AFAF), this day promotes the right of scholars and students to explore, teach, and publish ideas without fear of censorship or institutional repression. The date was chosen to mark the birthday of John Stuart Mill, author of On Liberty, a foundational work on free thought. Observed mostly in academic circles, it aims to raise awareness about ongoing challenges to intellectual independence in educational settings.

International Dinosaur Day* (Third Tuesday in May): This observance was likely started by educators to spark curiosity about dinosaurs and paleontology. It’s a great opportunity for students and enthusiasts alike to explore Earth’s prehistoric past, from the fearsome Tyrannosaurus rex to the towering Brachiosaurus. Activities often include museum visits, fossil-themed crafts, and classroom lessons. A similar observance takes place on June 1.

International Red Sneakers Day: Founded in 2018 by the nonprofit Red Sneakers for Oakley™, this day raises awareness about the seriousness of food allergies. It honors Oakley Debbs, an 11-year-old boy who tragically passed away in 2016 due to a severe allergic reaction to nuts. His signature red sneakers became the symbol of the campaign. The organization, started by his parents Merrill and Robert Debbs, uses this day to educate the public, advocate for better labeling, and promote allergy-safe practices.

National Band Director’s Day: This observance was established in 2020 by Russell Smith to recognize the vital role band directors play in shaping students’ musical growth and supporting arts education. The day encourages communities and schools to celebrate the dedication, mentorship, and lasting impact of band leaders across the country.

National Be a Millionaire Day: Celebrated annually on May 20, this day invites people to reflect on financial goals and dream big. While its origins are unclear, the day has become a fun opportunity to explore the habits and planning strategies that can lead to wealth. It also encourages people to think about how they would use financial success for personal growth or social good.

💰 A related celebration, National Financial Awareness Day, takes place on August 14. I have designed dozens of free savings trackers you can download on DigitalHygge for free.

National High Heel Day: Founded in 2021 by Kimberly Lorenz and Judge Gisela Laurent, this day celebrates high heels as symbols of empowerment and expression. More than a fashion statement, high heels often represent strength, identity, and confidence for many people. The day also promotes inclusivity and confidence in professional environments.

👠 Similar days that encourage self-expression through clothing are: National Dress Day on March 6, National Hat Day on January 15, and National Scarf Day on September 27.

National Pick Strawberries Day: Held every May 20, this day celebrates the joy of harvesting fresh strawberries during peak season. Whether eaten raw, baked into desserts, or made into jam, strawberries offer both flavor and nutrition. This day complements National Strawberry Day on February 27, which marks the symbolic start of strawberry season, while this later date encourages people to enjoy the fruit freshly picked.

National Quiche Lorraine Day: This food holiday honors a classic French dish made with a flaky crust, eggs, cream, bacon, and Swiss cheese. Originating in the Lorraine region—once under German rule—quiche Lorraine became popular outside France in the mid-20th century. Though many variations exist today, traditionalists insist the authentic recipe includes no vegetables or alternative meats.

🍽️ Similar culinary observances include National Cheese Lover’s Day on January 20 and National Homemade Bread Day on November 17.

National Rescue Dog Day: Started in 2018 by Lisa Wiehebrink, founder of Tails That Teach, this day promotes the adoption of rescue dogs and highlights the transformative bond they create with their new families. Inspired by Cooper, a rescue pup from Los Angeles, the day raises awareness of shelter dog populations and encourages responsible pet ownership.

National Days for Dog Lovers 2025

National Streaming Day: Launched by Roku in 2014 to celebrate its 10th anniversary, this day acknowledges how streaming services have changed the way we access entertainment. From music and movies to educational content, streaming platforms have made information and enjoyment more accessible. The observance also celebrates ongoing advances in technology and encourages users to explore new digital formats.

National SugarBee® Apple Day: Celebrated since 2013, National SugarBee® Apple Day honors the unique apple variety discovered by Chuck Nystrom in Worthington, Minnesota. This apple came from a chance pollination between a Honeycrisp and an unknown variety—thanks to a honeybee. With its caramel-like sweetness and long shelf life, SugarBee® apples have grown in popularity across the U.S. The day was established to celebrate this naturally created fruit and encourage consumers to enjoy its crisp texture and rich flavor.

🍎 Other apple-themed observances are: National Apple Day on October 21 and National Eat a Red Apple Day on December 1.

National Women in Aerospace Day: Started in 2021 by Nikki Malcom, executive director of the Pacific Northwest Aerospace Alliance, this day recognizes the vital contributions of women in aviation, aerospace engineering, and space exploration. It also promotes STEM opportunities for young girls and highlights the need for more representation in technical fields. Celebrations often include school events, industry talks, and community programs.

👩 Related observances include International Women in Engineering Day on June 23 and International Day of Women and Girls in Science on February 11.

World Autoimmune Arthritis Day: Created in 2012 by the International Autoimmune Arthritis Movement (now AiArthritis), this day brings attention to diseases where the immune system mistakenly attacks joints and tissues. Conditions like rheumatoid arthritis, lupus, and ankylosing spondylitis often go misdiagnosed or misunderstood. Through global events, patient stories, and advocacy, the day fosters understanding, drives research, and connects patients with resources.

🩻 World Autoimmune Arthritis Day complements awareness days like World Lupus Day on May 10 and World Arthritis Day on October 12.

World Bee Day: Declared by the United Nations in 2017, World Bee Day shines a spotlight on the importance of bees and other pollinators. May 20 was chosen to mark the birthday of Anton Janša, a pioneer of modern beekeeping born in Slovenia in 1734. The day emphasizes the ecological role bees play in food security and biodiversity. With threats like habitat loss and pesticide use affecting bee populations worldwide, this observance encourages sustainable farming and pollinator-friendly practices.

World Metrology Day / Weights & Measures Day: Observed annually on May 20, World Metrology Day commemorates the signing of the Metre Convention in 1875, which laid the foundation for a unified international system of measurement. Seventeen nations came together that day to standardize units like the meter and kilogram. The celebration highlights the importance of accurate and consistent measurement in science, industry, and trade. Events are organized by national metrology institutes and the International Bureau of Weights and Measures (BIPM), connecting this day to ongoing advancements in measurement science.