May 2024 observances

Calan Mai

Welsh seasonal folk tradition associated with the traditional beginning of summer

Wales.com, the official Welsh destination site, identifies Calan Mai on 1 May and describes its traditional seasonal customs.

Global Love Day

organizer-led global compassion and human-connection observance

The Love Foundation; first celebrated in 2004

International Doodle Dog Day

International / creator-led doodle-dog community observance

The official International Doodle Dog Day site states that doodle dog lovers celebrate every year on May 1 and identifies Jeannie North as the founder.

International Sunflower Guerrilla Gardening Day

International / guerrilla-gardening community observance

GuerrillaGardening.org documents International Sunflower Guerrilla Gardening Day on 1 May and says Brussels guerrilla gardeners declared it in 2007.

Keep Kids Alive Drive 25 Day

United States / Keep Kids Alive Drive 25 road-safety campaign

Keep Kids Alive Drive 25 identifies May 1 as KKAD25 Day and describes the 2026 observance as its 20th annual nationwide proclamation effort.

Labor Day (Philippines)

Philippine regular holiday

Supreme Court E-Library / official presidential proclamation

Lei Day

Hawaiʻi cultural observance recognized by the state

State of Hawaiʻi Department of Land and Natural Resources / state law history

Constitution Day

Republic of the Marshall Islands / national Constitution Day

The Republic of the Marshall Islands Embassy country profile lists Constitution Day on May 1 among the country’s national holidays and notes adoption of the Constitution on May 1, 1979.

May Day / International Workers’ Day

International labour movement observance; public-holiday status varies by country

The International Labour Organization marks May Day on 1 May and publishes current worker-focused material.

National Mother Goose Day

United States-origin literary and nursery-rhyme observance

A New York State Senate resolution identifies Gloria T. Delamar as establishing Mother Goose Day in 1987 alongside publication of her Mother Goose reference work; calendar documentation con…

National Black Barber Shop Appreciation Day

United States / creator-registered appreciation observance

National Day Archives records National Black Barber Shop Appreciation Day for May 1 and attributes its 2021 creation to James Jean-Pierre.

National Chocolate Parfait Day

Informal food-calendar usage documented by Association of Nutrition & Foodservice Professionals chapter material

Two Association of Nutrition & Foodservice Professionals chapter calendars list National Chocolate Parfait Day on 1 May.

National Interpreter Appreciation Day

United States / interpreter appreciation observance

Minnesota Judicial Branch explicitly references National Interpreter Appreciation Day on Wednesday, May 6, 2026; Illinois court and public-school calendars place the observance on Wednesday…

Law Day, U.S.A.

United States patriotic and national observance

United States Code, title 36 §113

Loyalty Day

United States patriotic and national observance

United States Code, title 36 §115

National Purebred Dog Day

United States / dog-community recognition

The American Kennel Club identifies 1 May as National Purebred Dog Day and its May 2026 Gazette explicitly celebrates the date.

National Rotate Your Beer Day

United States / informal beer-retail observance

National Day Archives records National Rotate Your Beer Day on May 1 and attributes it to Superior Beverage Group, while Days Of The Year independently places it on May 1.

Save the Rhino Day

International Rhino Foundation / conservation-awareness context

The International Rhino Foundation identifies May 1 as Save the Rhino Day in its conservation communications.

School Principals Day

United States / school-principal recognition observance corroborated by California education calendar

The California Department of Education’s 2026 and 2027 recognition calendars both state that May 1 should be recognized annually as School Principals Day.

Therapeutic Massage Awareness Day

International / informal therapeutic-massage awareness observance

National Today and Days Of The Year independently place Therapeutic Massage Awareness Day on May 1 each year.

International Scurvy Awareness Day

International / informal scurvy-awareness observance

Checkiday and AnydayGuide independently place International Scurvy Awareness Day on May 2 each year.

National Brothers and Sisters Day

United States / informal sibling-appreciation observance

National Today gives National Brothers and Sisters Day a fixed May 2 recurrence, and Days Of The Year independently lists it among the May 2 observances.

National Day of Prayer

United States national prayer observance

36 U.S.C. §119

National Life Insurance Day

United States / Liran Hirschkorn-created life-insurance awareness observance

National Day Calendar identifies Liran Hirschkorn as the founder, records the submission in 2014, and observes National Life Insurance Day annually on May 2.

National Play Your Ukulele Day

United States / informal music-participation observance

National Today and Checkiday independently place National Play Your Ukulele Day on May 2 each year.

Polish National Flag Day / National Flag Day of the Republic of Poland

Poland / national flag observance

Poland’s National Security Bureau states that Polish National Flag Day is celebrated on May 2 and was established by the Sejm in 2004 to commemorate the history and significance of the nati…

World Password Day

Cybersecurity-awareness observance

Erie County Consumer Protection identifies World Password Day as the first Thursday in May and frames it around stronger password habits

World Tuna Day

United Nations / international observance

A/RES/71/124

Constitution Memorial Day

Japan / national holiday

Japan’s Cabinet Office identifies Constitution Memorial Day on 3 May and explains that it commemorates the enforcement of the Constitution and hopes for national development.

Día de la Cruz

El Salvador cultural-religious tradition

El Salvador’s Ministry of Culture describes Día de la Cruz on 3 May as an important Salvadoran celebration with syncretic Christian and Indigenous elements.

Wild Koala Day

international wild-koala awareness and conservation observance

Wild Koala Day organizers

National Montana Day

United States / National Day Calendar National State Days series — Montana

National Day Calendar lists National Montana Day on 3 May. The U.S. Senate records Montana’s admission/statehood date as 8 November 1889. The two dates are deliberately kept separate so the…

National No Pants Day

United States / informal novelty observance

National Today and Days Of The Year independently define No Pants Day as the first Friday in May each year.

National Public Radio Day

United States / informal public-radio appreciation observance

National Today gives National Public Radio Day a fixed May 3 recurrence, and New Hampshire PBS independently acknowledges National Public Radio Day on May 3 in its dated educational calenda…

National Raspberry Pop Over Day

United States / informal food observance

National Today and National Day Calendar independently place National Raspberry Pop Over / Popover Day on May 3 each year.

National SAN Architect Day

United States / KCI, Inc.-submitted professional recognition observance

National Day Calendar states that KCI, Inc. founded/submitted National SAN Architect Day and that the Registrar proclaimed it to be observed annually on May 3.

National Specially-Abled Pets Day

United States-origin / creator-led disabled-pet awareness observance

National Day Calendar records May 3 as National Specially-Abled Pets Day and attributes its founding to animal advocate Colleen Paige; archived creator material is also referenced by indepe…

World Press Freedom Day

UNESCO / United Nations international observance

UNESCO 26 C/Resolution 4.3

Firefighters’ Memorial Day

United Kingdom / firefighters remembrance

The Firefighters Memorial Trust says Firefighters’ Memorial Day is marked each year on 4 May to remember firefighters who have died in service.

Greenery Day (Midori no Hi)

Japanese national holiday

Cabinet Office of Japan; Act on National Holidays

International Firefighters Day

International firefighter recognition observance

Pilates Day / International Pilates Day

International Pilates professional-community observance

The Pilates Method Alliance maintains a current 2026 Pilates Day planning kit; historical professional sources document the PMA’s International Pilates Day initiative.

International Respect for Chickens Day

International / United Poultry Concerns advocacy project

United Poultry Concerns identifies International Respect for Chickens Day as an annual May 4 project and traces the campaign to its 2005 launch.

May 4 Day of Remembrance

Kent State University / May 4, 1970 remembrance

Kent State University says May 4 was established as an official Day of Remembrance in 1977 and documents annual May 4 commemorations.

World Naked Gardening Day

International grassroots gardening/body-acceptance observance

The Naturist Education Foundation’s WNGD page states that World Naked Gardening Day is always the first Saturday in May and gives 2 May 2026.

National Candied Orange Peel Day

Informal food-calendar usage documented by Association of Nutrition & Foodservice Professionals chapter material

ANFP chapter calendar material lists National Candied Orange Peel Day on May 4.

National Day of Reason

United States / secular observance promoted by the American Humanist Association and partner organizations

The current National Day of Reason campaign and American Humanist Association identify May 4 as the annual observance date; a 2026 U.S. House resolution also recognizes May 4, 2026 without…

National Explosive Ordnance Disposal Day

U.S. recognition and memorial context for explosive ordnance disposal personnel

U.S. House Resolution 1294 supports designating the first Saturday in May as National Explosive Ordnance Disposal Day, and EOD Warrior Foundation material continues the memorial observance.

National Fitness Day

United States / National Fitness Day organization

The National Fitness Day organization states that the observance started in 2017 and is celebrated on the first Saturday of May in the United States.

National Kids Fitness Day

United States / informal children’s fitness observance

UCLA Health explicitly highlights National Kids Fitness Day on May 4 during National Fitness Month, and Days Of The Year independently places the observance on May 4.

National Orange Juice Day

United States / informal food observance with Florida citrus-industry and university corroboration

The Florida Department of Citrus and University of Florida IFAS materials repeatedly identify May 4 as National Orange Juice Day.

Remembrance Day

Netherlands / national remembrance observance

The Government of the Netherlands states that each year at 20:00 on 4 May a two-minute silence is observed for victims of the Second World War.

National Scrapbook Day

Scrapbooking community / Creative Memories-origin observance

Creative Memories states that the first Saturday in May is National Scrapbook Day and continues to publish current NSD materials; its history identifies Creative Memories as the originator.

National Start Seeing Monarchs Day

United States / monarch-butterfly awareness observance

The City of Hoboken recognized 2 May 2026 as National Start Seeing Monarchs Day, while the current observance registry gives the reusable rule as the first Saturday of May.

Rhode Island Independence Day

Rhode Island, United States / state independence commemoration

Rhode Island government sources state that 4 May each year is established as Rhode Island Independence Day, commemorating the General Assembly’s 4 May 1776 Act renouncing allegiance to the…

Star Wars Day / May the 4th

Star Wars / Lucasfilm fan-culture observance

StarWars.com documents May 4 as Star Wars Day and the worldwide “May the 4th” celebration.

Wildfire Community Preparedness Day

United States and Canada / NFPA preparedness campaign

NFPA’s campaign fact sheet identifies Wildfire Community Preparedness Day as the first Saturday in May and gives 2 May for 2026.

World AS Day

global axial spondyloarthritis awareness observance

Axial Spondyloarthritis International Federation (ASIF)

World Give Day

International / informal giving observance

National Today and Days Of The Year independently place World Give Day on May 4 each year.

African World Heritage Day

UNESCO world day

International Bereaved Mother’s Day

International grief/remembrance observance for mothers whose children have died

Founder Carly Marie’s published account states that International Bereaved Mother’s Day was created in 2010 and is held on the first Sunday of May; current bereavement organizations observe…

Kodomo no Hi (Children’s Day)

Japan / national holiday

Japan’s Cabinet Office identifies Kodomo no Hi as a national holiday on 5 May under the national-holiday framework.

Indian Arrival Day

Guyana national commemoration

Office of the President of Guyana

International Dawn Chorus Day

The Wildlife Trusts / international nature-listening participation

The Wildlife Trusts identifies International Dawn Chorus Day on the first Sunday in May and describes the celebration of birdsong at dawn

International Day of the Midwife

Organizer-backed international observance

International Confederation of Midwives (ICM)

Liberation Day (Bevrijdingsdag)

Netherlands / public holiday

The Government of the Netherlands lists Liberation Day on 5 May among Dutch public holidays, including 5 May in the official 2026 and 2027 holiday schedules.

National Astronaut Day

U.S. spaceflight appreciation observance tied to Alan Shepard’s 1961 Freedom 7 flight

The White House issued a National Astronaut Day message on 5 May 2026 honoring Alan Shepard’s first American human spaceflight; the observance’s organizer describes May 5 as the annual date.

National Cartoonists Day

United States / cartoonist-recognition observance associated with the National Cartoonists Society

Established publication coverage identifies May 5 as National Cartoonists Day and attributes the observance to the National Cartoonists Society, tied to early color newspaper cartoon histor…

National Chocolate Custard Day

Informal food-calendar usage documented by Association of Nutrition & Foodservice Professionals chapter material

Two Association of Nutrition & Foodservice Professionals chapter calendars list National Chocolate Custard Day on 5 May.

National Silence the Shame Day

Silence the Shame nonprofit mental-health awareness campaign

Silence the Shame identifies 5 May as Silence the Shame Day, focused on reducing stigma and encouraging open discussion around mental wellness.

World Hand Hygiene Day

World Health Organization campaign

WHO SAVE LIVES: Clean Your Hands campaign

World Laughter Day

international laughter and positive-community observance

Laughter Yoga International

World Portuguese Language Day

UNESCO / international observance

UNESCO 40 C/Resolution 70 (formal adopted act; 40 C/75 is a separate General Conference document identifier)

Great Lakes Awareness Day

United States / informal Great Lakes environmental-awareness observance

National Today uses the first Monday in May, while Checkiday’s target-year listing corroborates the equivalent first-full-week Monday recurrence.

Melanoma Monday®

American Academy of Dermatology U.S. skin-cancer awareness campaign

The American Academy of Dermatology says it launched Melanoma Monday in 1995, observes it every year on the first Monday in May, and identifies 4 May as the 2026 date.

National Beverage Day

United States / informal food-and-drink observance

Independent observance calendars identify May 6 as National Beverage Day.

National Nurses Day

United States / nursing professional recognition

The American Nurses Association records that its Board formally acknowledged May 6, 1982 as National Nurses Day; May 6 remains the opening date of National Nurses Week.

National Tourist Appreciation Day

United States / informal tourism-appreciation observance

National Today and Days Of The Year independently place National Tourist Appreciation Day on May 6 each year.

No Homework Day

United States / creator-defined informal Wellcat observance

The first-party Wellcat Holidays calendar lists No Homework Day on May 6 and identifies the holiday collection as created by Thomas and Ruth Roy.

Jose Abad Santos Day

Province of Pampanga and City of Angeles, Philippines — special nonworking holiday

Republic Act No. 8815 amending Republic Act No. 7552

National Packaging Design Day

United States-origin packaging-design industry observance

Davis Publications states that Design Packaging established National Packaging Design Day in 2015; National Day Calendar’s creator-history page gives the annual May 7 date.

National Roast Leg of Lamb Day

Informal food-calendar usage documented by Association of Nutrition & Foodservice Professionals chapter material

Two Association of Nutrition & Foodservice Professionals chapter calendars list National Roast Leg of Lamb Day on 7 May.

World Asthma Day

Organizer-backed international observance

Global Initiative for Asthma (GINA)

National Coconut Cream Pie Day

United States / informal food observance

Independent observance calendars identify May 8 as National Coconut Cream Pie Day.

National Give Someone a Cupcake Day

United States / informal food-and-kindness observance

National Today gives National Give Someone a Cupcake Day a fixed May 8 recurrence, and EventGuide independently lists it as an every-May-8 observance.

National Night Shift Workers Day

United States / informal workplace appreciation observance

Current observance references place National Night Shift Workers Day / National Third Shift Workers Day on the second Wednesday in May.

National Report Government Contractor Fraud Day

United States / Hesch Firm fraud-reporting awareness campaign

A Hesch Firm-issued PRWeb release states the day is celebrated May 8 and says Joel D. Hesch formed the observance in 2018.

National Student Nurses Day

United States / student nursing recognition

The American Nurses Association states that in 1997 its Board, at the request of the National Student Nurses Association, designated May 8 as National Student Nurses Day.

National Third Shift Workers Day

United States / third-shift worker appreciation observance

UFCW materials identify National Third Shift Workers Day on the second Wednesday in May, with dated examples consistent with the recurrence rule.

No Socks Day

United States / creator-defined informal Wellcat observance

The first-party Wellcat Holidays calendar lists No Socks Day on May 8 and identifies the holiday collection as created by Thomas and Ruth Roy.

National Receptionists Day

United States / workplace appreciation observance

New York Senate Resolution J5006 describes National Receptionists Day as the second Wednesday in May and records its 1991 creation by the Director of the National Receptionists Association.

Root Canal Appreciation Day

United States / informal dental-awareness observance

Multiple observance archives identify the second Wednesday in May recurrence and attribute the 2005 creation to dentist Dr. Chris Kammer; archived press-release references support the creat…

Time of Remembrance and Reconciliation for Those Who Lost Their Lives During the Second World War

United Nations / international observance

A/RES/59/26

Truman Day

Missouri state holiday/commemorative day

Missouri Revised Statutes / Office of the Governor

Victory in Europe Day (VE Day)

United Kingdom and wider European remembrance of the end of the Second World War in Europe

UK government material marks 8 May as VE Day and commemorates the end of the Second World War in Europe.

White Lotus Day

Theosophical Society commemorative tradition

The Theosophical Society in Australia documents White Lotus Day as the annual 8 May commemoration associated with Helena P. Blavatsky.

World Ovarian Cancer Day

International / World Ovarian Cancer Coalition campaign

The World Ovarian Cancer Coalition states that World Ovarian Cancer Day was established in 2013 and that its global community stands together on May 8 each year.

World Red Cross and Red Crescent Day

Organizer-backed international observance

International Red Cross and Red Crescent Movement

Europe Day

European Union observance

European Union and European Commission

Liberation Day

Guernsey / public holiday and liberation remembrance

The States of Guernsey public-holiday calendar lists Liberation Day on 9 May 2026, and official Liberation Day planning material uses 9 May for island commemorations.

Victory Day

Russia / national military and historical commemoration

The Kremlin’s official Victory Day material documents the national celebrations and military parade on 9 May.

Saint Damien de Veuster Day

Hawaii, United States / statutory commemorative day; not a state holiday

Hawaii Revised Statutes §8-8 designates May 10 of each year as Saint Damien de Veuster Day and expressly provides that the day is not a state holiday; the 2010 amendment replaced the older…

International Day of Argania

United Nations / international observance

A/RES/75/262

FSM Constitution Day

Federated States of Micronesia / national Constitution Day

The FSM Government’s Constitution Day messages identify May 10 with the coming into force of the Constitution in 1979 and continue to mark FSM Constitution Day in current government communi…

Día de las Madres in Mexico

Mexico / national social observance

Mexico’s National Population Council documents Día de las Madres on May 10 and traces the Mexican commemoration to 1922.

National Clean Your Room Day

United States / informal cleaning and home-organization observance

National Today uses National Clean Your Room Day on May 10, while National Day Calendar uses the closely matching name National Clean Up Your Room Day on the same annual date.

National Miniature Golf Day

United States / informal miniature-golf observance

National Day Archives lists National Miniature Golf Day on May 10; the shorter public “Mini Golf” title is treated as an alias.

National Shrimp Day

Informal food-calendar usage documented by Association of Nutrition & Foodservice Professionals chapter material

Two Association of Nutrition & Foodservice Professionals chapter calendars list National Shrimp Day on 10 May.

National Small Business Day

United States / informal small-business appreciation observance, distinct from SBA National Small Business Week

Economic-development and calendar materials identify May 10 as National Small Business Day while separately recognizing the SBA’s National Small Business Week.

National Washington Day

United States / National Day Calendar National State Days series — Washington

National Day Calendar lists National Washington Day on 10 May. The U.S. Senate records Washington’s admission/statehood date as 11 November 1889. These are separate facts: the calendar list…

National Independence Day of Romania (Ziua Independenței Naționale a României)

Romania / national commemorative day

A 2026 Romanian prefecture notice states that, following Law 189/2021, the Romanian state has commemorated National Independence Day every year on 10 May since 2022.

World Lupus Day

Organizer-backed international observance

World Lupus Federation and the global lupus community

International CdLS Awareness Day

International / CdLS Foundation awareness observance

The CdLS Foundation says International CdLS Awareness Day is observed on the second Saturday in May each year and lists the 2026 edition for 9 May.

National Dog Mom’s Day

United States / dog-caregiver appreciation observance

Current pet calendars consistently place National Dog Mom’s Day on the second Saturday in May; the observance is traced to a 2018 launch associated with Dig.

World Fair Trade Day

World Fair Trade Organization / global fair-trade movement

The World Fair Trade Organization identifies World Fair Trade Day on the second Saturday in May

Hostess CupCake Day

United States / informal branded-food observance

National Today and Days Of The Year independently list Hostess CupCake Day on May 11 every year.

Eat What You Want Day

United States / creator-defined informal Wellcat observance

The first-party Wellcat Holidays calendar lists Eat What You Want Day on May 11 and identifies the Wellcat holiday collection as created by Thomas and Ruth Roy.

National Technology Day (India)

India / national science and technology observance

India’s Department of Science and Technology identifies 11 May as National Technology Day, commemorated annually following the 1998 technology achievements.

World Belly Dance Day

International / belly-dance community observance

A Bayfield County, Wisconsin 2026 event page explicitly states that the second Saturday in May is World Belly Dance Day; dance-community historical references attribute the concept to Lydia…

World Ego Awareness Day

International / Ego Awareness Movement campaign

The Ego Awareness Movement identifies May 11 as World Ego Awareness Day and states that the observance was established in 2018.

World Fair Trade Day

international Fair Trade awareness and economic-justice observance

World Fair Trade Organization (WFTO)

World Migratory Bird Day

UNEP-supported global conservation campaign

UNEP / CMS / AEWA partner campaign

ME/CFS Awareness Day

International ME/CFS awareness / CDC public-health recognition

The U.S. Centers for Disease Control and Prevention states that May 12 marks ME/CFS International Awareness Day and presents it as an annual awareness observance.

Fibromyalgia Awareness Day / International Fibromyalgia Awareness Day

Fibromyalgia advocacy community / current Canadian and U.S. state recognition

Fibromyalgia Association Canada states that Fibromyalgia Awareness Day is observed annually on May 12; current 2026 government proclamations in Michigan also recognize May 12 for the year.

ME/CFS International Awareness Day

International / ME/CFS awareness

CDC states that May 12 marks the international awareness day for ME/CFS and describes it as an annual observance; NIH separately identifies May 12 as ME/CFS and Fibromyalgia International A…

International Day of Plant Health

United Nations / FAO international observance

A/RES/76/256

International ME/CFS Awareness Day

International ME/CFS awareness / patient-advocacy context

#MEAction identifies 12 May as Myalgic Encephalomyelitis awareness day and documents International ME/CFS Awareness Day usage.

International Nurses Day

International Council of Nurses professional observance

Mother’s Day — United States statutory observance

United States / federal statutory observance

36 U.S.C. §117 designates the second Sunday in May as Mother’s Day and requests an annual presidential proclamation.

National Infertility Survival Day

United States / unofficial infertility-awareness and self-care observance

A New York Senate resolution identifies Beverly Barna as the creator and states that National Infertility Survival Day is observed each year on the Sunday prior to Mother’s Day.

National Mental Health Provider Appreciation Day

United States / Anne C. Totero-created appreciation observance; separately proclaimed in Wisconsin in sourced years

Founder Anne C. Totero states that she created Mental Health Provider Appreciation Day in 2020 for May 12 and documents Wisconsin proclamations beginning in 2022; the creator continues the…

National Public Gardens Day

United States / American Public Gardens Association awareness initiative

The American Public Gardens Association documents National Public Gardens Day as an annual tradition on the Friday preceding Mother’s Day weekend and records its inauguration in 2009.

National Tampon Day

United States / TOP (The Organic Project) creator-defined period-awareness observance

National Day Archives records May 12 and identifies TOP, The Organic Project, as the 2020 founder of National Tampon Day.

Children of Fallen Patriots Day

United States / state and local commemorative recognition

Michigan's governor proclaimed May 13, 2019 as Children of Fallen Patriots Day, and current state/local government calendars continue to recognize May 13.

IEEE Global Engineering Day

International informal engineering recognition associated with IEEE communities

IEEE community event infrastructure shows observance activity around IEEE Global Engineering Day, while established calendar sources consistently place the named observance on May 13. The e…

National Apple Pie Day

United States / informal food observance

Independent observance calendars identify May 13 as National Apple Pie Day.

National Frog Jumping Day

United States / informal literary-history-inspired observance

National Day Calendar lists National Frog Jumping Day on May 13, and the Richmond Public Library independently includes May 13 while noting the Mark Twain frog-jumping literary connection.

National Fruit Cocktail Day

Informal food-calendar usage documented by Association of Nutrition & Foodservice Professionals chapter material

Two Association of Nutrition & Foodservice Professionals chapter calendars list National Fruit Cocktail Day on 13 May.

National Women’s Checkup Day

U.S. women’s preventive-health awareness; historical federal health-campaign usage and current state recognition

A 2026 New York Senate resolution identifies National Women’s Checkup Day as held annually on the second Monday in May and recognizes May 11, 2026 in conjunction with the observance.

Top Gun Day

International / unofficial Top Gun fan observance

The dedicated Top Gun Day site explicitly identifies May 13 as Top Gun Day and maintains future-year countdown information for the date.

International Chihuahua Appreciation Day

International informal companion-animal appreciation observance / creator-maintained source

Famous Chihuahua’s creator site states that International Chihuahua Appreciation Day is celebrated every year on May 14 and connects the date to the site’s Chihuahua community history.

International Dylan Thomas Day

international literary observance celebrating Dylan Thomas

Literature Wales and Dylan Thomas partners

National Travel Insurance Claims Day

United States / travel-insurance industry recognition observance

The U.S. Travel Insurance Association observes National Travel Insurance Claims Day on May 14, while Aon Affinity Travel states that its travel practice started the day in 2019.

Paraguay Independence Day

Paraguay

The Organization of American States’ current country page lists Paraguay National Independence Day as 14 May.

International HG Awareness Day (HGAD)

HER Foundation / hyperemesis gravidarum awareness campaign

The HER Foundation’s 2026 campaign page states that May 15 is International HG Awareness Day.

International Casinos Day

International / casino-industry observance created by Casinos.com

Casinos.com states that it established International Casinos Day in 2025 for May 15 and displays a City of Las Vegas proclamation; EventGuide independently records an every-May-15 recurrenc…

International Conscientious Objection Day

international solidarity observance for conscientious objectors

War Resisters’ International and partner peace organizations

International Day of Families

United Nations / international observance

A/RES/47/237

Kangaroo Care Day® / International Kangaroo Care Awareness Day

Global organizer-led skin-to-skin-care awareness

The official Kangaroo Care Day site identifies May 15 as the annual global awareness initiative, founded in 2011, and publishes dedicated 2026 materials for May 15.

National Chocolate Chip Day

Informal food-calendar usage documented by Association of Nutrition & Foodservice Professionals chapter material

ANFP chapter calendar material lists National Chocolate Chip Day on May 15.

National Employee Health and Fitness Day

United States / National Association for Health & Fitness workplace-wellness observance

The U.S. President’s Council historical record identifies the NAHF activity and states that National Employee Health and Fitness Day is held on the third Wednesday of May.

National Safety Dose Day

United States / informal medication-safety awareness observance

National Today and EventGuide independently place National Safety Dose Day on May 15 every year.

Peace Officers Memorial Day

United States

The White House’s 2026 proclamation states that law authorizes 15 May of each year as Peace Officers Memorial Day.

Spinal Cord Injury Awareness Day

United Kingdom / spinal-cord-injury charity coalition awareness day

Spinal Injuries Association describes SCIAD as an annual event, while Spinal Research and the UK Parliament identify 15 May 2026; earlier UK charity material also marks May 15, supporting t…

TSC Global Awareness Day

TSC International / TSC Alliance global awareness campaign

The TSC Alliance states that TSC International coordinates TSC Global Awareness Day each year on May 15.

Vascular Birthmarks Awareness Day

International / Vascular Birthmarks Foundation-led awareness campaign

The Vascular Birthmarks Foundation identifies May 15 as its Day of Awareness for vascular birthmarks, anomalies and related syndromes.

VBF Day of Awareness

International / Vascular Birthmarks Foundation-led awareness campaign

The Vascular Birthmarks Foundation identifies May 15 as the Day of Awareness for vascular birthmarks, anomalies and related syndromes.

Global Accessibility Awareness Day

Organizer-backed global digital-accessibility observance

GAAD Foundation

International Day of Light

UNESCO international observance

UNESCO 39 C/Resolution 16

International Day of Living Together in Peace

United Nations / international observance

A/RES/72/130

National Aperitif Day

United States / informal aperitif observance

National Today and Checkiday independently define National Apéritif Day as the third Thursday in May each year.

National Barbecue Day

United States / informal barbecue-food observance

National Day Calendar states that National Barbecue Day is celebrated each year on May 16, and National Today independently gives National BBQ Day an every-May-16 recurrence.

National Coquilles Saint Jacques Day

United States / informal food observance

National Day Calendar and National Today independently place National Coquilles Saint Jacques Day on May 16.

National Do Something Good for Your Neighbor Day

United States / Starr Valentino-created neighbor-kindness observance with local civic proclamations

A City of Huntsville proclamation identifies May 16 as National Do Something Good for Your Neighbor Day and credits Starr Valentino with beginning the observance in Atlanta in 2009.

National Honor Our LGBT Elders Day

United States / elder-recognition observance supported by SAGE and the National Resource Center on LGBTQ+ Aging

SAGE/National Resource Center materials identify May 16 as National Honor Our LGBT Elders Day; congressional resolutions have also recognized the observance.

National Love a Tree Day

United States / tree-appreciation observance acknowledged by university extension

University of California Agriculture and Natural Resources published a 2026 article explicitly in celebration of National Love a Tree Day on May 16.

National Notebook Day

United States-origin stationery / notebook appreciation observance

The inaugural 2016 announcement identifies May Designs as the creator; subsequent coverage records the recurring rule as the third Thursday in May.

Endangered Species Day

United States conservation awareness observance

U.S. Fish & Wildlife Service

International Child Helpline Day

Child Helpline International / global network observance

Child Helpline International identifies 17 May as International Child Helpline Day; its materials also document the observance’s network context.

International Day against Homophobia, Transphobia and Biphobia (IDAHOBIT)

Global decentralized equality and human-rights observance

The IDAHOBIT campaign’s 2026 material identifies May 17 as the International Day against Homophobia, Transphobia and Biphobia and describes global participation around the date.

International Virtual Assistants Day

International / virtual-assistant professional recognition associated with OIVAC

The original 2006 announcement and later OIVAC materials describe International Virtual Assistants Day as the third Friday of May each year.

Bike to Work Day

United States / League of American Bicyclists National Bike Month

The League of American Bicyclists lists Bike to Work Day on May 15, 2026 and explicitly gives the future-date rule as the third Friday in May.

National Defense Transportation Day

United States / federal patriotic and national observance framework

36 U.S.C. §120 requests an annual presidential proclamation designating the third Friday in May as National Defense Transportation Day and recognizing the importance of the U.S. transportat…

National Idaho Day

United States / National Day Calendar National State Days series — Idaho

National Day Calendar lists National Idaho Day on 17 May. The U.S. Senate records Idaho’s admission/statehood date as 3 July 1890. The two dates are deliberately kept separate so the inform…

National Pizza Party Day

United States / informal food observance with explicit current first-party recurrence

Pizza Hut’s 2026 first-party page states that National Pizza Party Day is celebrated annually on the third Friday in May and falls on May 15 in 2026.

World NF Awareness Day

Children’s Tumor Foundation / global NF awareness campaign

The Children’s Tumor Foundation identifies 17 May as World NF Awareness Day and separately identifies 22 May for NF2-SWN awareness.

World Hypertension Day

Organizer-backed international observance

World Hypertension League (WHL)

World Telecommunication and Information Society Day

ITU / United Nations / international observance

A/RES/60/252

Fête du Drapeau et de l’Université

Haiti / national flag and university observance

The Government of Haiti documented official 18 May 2025 ceremonies for the Fête du Drapeau et de l’Université and described the date’s national symbolic importance.

International Museum Day

International Council of Museums global observance

National Cheese Soufflé Day

Informal food-calendar usage documented by Association of Nutrition & Foodservice Professionals chapter material

Two Association of Nutrition & Foodservice Professionals chapter calendars list National Cheese Soufflé Day on 18 May.

HIV Vaccine Awareness Day

United States / NIH HIV research awareness

NIH states that HIV Vaccine Awareness Day is held annually on May 18 and recognizes volunteers, community members, health professionals and scientists working on preventive HIV-vaccine rese…

National Learn to Swim Day™

United States / Swimways-founded water-safety awareness observance

Swimways states that it established National Learn to Swim Day in 2012 and that the observance is held on the third Saturday of May each year.

National Visit Your Relatives Day

United States / informal family-connection observance

National Day Calendar and National Today independently place National Visit Your Relatives Day on May 18; Days Of The Year also lists it on May 18.

Send An Electronic Greeting Card Day

United States / creator-defined informal Wellcat observance

The first-party Wellcat calendar lists Send An Electronic Greeting Card Day on May 18.

Constitution and State Flag Day

Turkmenistan

Turkmenistan government states the national observance is celebrated every year on 18 May

HIV Vaccine Awareness Day (HVAD)

United States / NIH HIV awareness observance

NIH HIVinfo states that HIV Vaccine Awareness Day is observed each year on May 18. The page title “World AIDS Vaccine Day” is treated as a search/legacy alias, not the authority’s official…

World Fiddle Day

international fiddle-music celebration

World Fiddle Day campaign; recurrence and history corroborated in Canada’s National Fiddling Day Act

National Hepatitis Testing Day

United States / CDC viral-hepatitis awareness

CDC’s 2026 Hepatitis Awareness Month material states that May 19 is National Hepatitis Testing Day and frames it as a reminder about viral hepatitis prevention, testing and treatment.

International AIDS Candlelight Memorial

Global Network of People Living with HIV / global memorial

The International AIDS Candlelight Memorial states that the memorial is held every third Sunday in May and has been observed since 1983 under coordination by GNP+.

National Asian & Pacific Islander HIV/AIDS Awareness Day

United States / Asian and Pacific Islander HIV awareness

HIV.gov states that National Asian & Pacific Islander HIV/AIDS Awareness Day is observed annually on May 19 and brings attention to HIV in Asian and Pacific Islander communities.

National Barber Mental Health Awareness Day

United States / barber-industry mental-health awareness observance

The National Association of Barbers identifies May 19 as Barber Mental Health Awareness Day and publishes industry-focused mental-health awareness guidance for the date.

National Devil’s Food Cake Day

Informal food-calendar usage documented by Association of Nutrition & Foodservice Professionals chapter material

Two Association of Nutrition & Foodservice Professionals chapter calendars list National Devil’s Food Cake Day on 19 May.

National Mechanical Dry Eye Day

United States / Bio-Tissue founder-led dry-eye awareness campaign

The day registry identifies May 19 and Bio-Tissue as the founder in 2020; independent observance coverage preserves the same annual date.

National Take Your Parents to the Playground Day

United States / PDPlay-created family/outdoor-play observance

PDPlay currently promotes the observance on the third Sunday in May, and National Day Calendar records the current recurrence while documenting PDPlay’s original 2009 creation.

World IBD Day

Organizer-backed international observance

International Federation of Crohn's & Ulcerative Colitis Associations (IFCCA) and participating patient organizations

World Fair Play Day

United Nations / international observance

A/RES/78/310

World Family Doctor Day

Organizer-backed international observance

World Organization of Family Doctors (WONCA)

National Day of Cameroon

Cameroon / National Day

The Presidency of Cameroon identifies May 20 as National Day and links the observance to the 1972 referendum establishing the Unitary State.

Clinical Trials Day

International clinical-research professional community; coordinated by ACRP and sector partners

The Association of Clinical Research Professionals states Clinical Trials Day is observed annually on 20 May and documents its 2026 recognition initiative.

Restoration of Independence Day

Timor-Leste

The Government of Timor-Leste’s 2026 commemoration material marks 20 May 2026 as the 24th anniversary of the Restoration of Independence. The published search title is treated as a common-l…

Independence Restoration Day

Timor-Leste / national public holiday and independence commemoration

Timor-Leste government material identifies 20 May as Independence Restoration Day and as a national holiday under the country’s public-holiday framework.

International Red Sneakers Day

food-allergy awareness observance

Red Sneakers for Oakley

National Rescue Dog Day

United States-origin / creator-led rescue-dog awareness observance

The National Rescue Dog Day site states that the observance is held annually on May 20 and was founded in 2018 by Lisa Wiehebrink/Tails That Teach.

National Women in Aerospace Day

United States / congressional recognition context

H. Res. 941 was introduced to recognize May 20 as National Women in Aerospace Day, and the Congressional Record documents a May 20, 2026 House recognition statement.

Supply Chain Professionals Day

International supply-chain profession / CSCMP-created recognition day

CSCMP announced the inaugural annual Supply Chain Professionals Day in 2018, and trade coverage records the recurring rule as the third Monday in May.

World AUTOimmune & AUTOinflammatory Arthritis Day

Global / International Foundation for Autoimmune & Autoinflammatory Arthritis campaign

AiArthritis identifies 20 May as World AUTOimmune & AUTOinflammatory Arthritis Day and says the awareness day was established in 2012.

World Bee Day

FAO / United Nations / international observance

A/RES/72/211

World Metrology Day

UNESCO international day

UNESCO international day

World Day for Cultural Diversity for Dialogue and Development

United Nations / UNESCO international observance

A/RES/57/249

International Tea Day

United Nations / FAO international observance

A/RES/74/241

National Stop Nausea Day

United States / Reliefband-created nausea-awareness observance

Reliefband Technologies states that it created National Stop Nausea Day and that it is celebrated on the third Tuesday in May each year.

National Waiters and Waitresses Day

United States / hospitality-industry appreciation observance

Bar & Restaurant identifies May 21 as National Waiters and Waitresses Day in a dedicated 2014 article and in multiple hospitality promotional calendars.

National Waitstaff Day

United States / waitstaff appreciation observance

The U.S. Census Bureau has published National Waitstaff Day material for May 21, providing federal institutional recognition of the date.

Día de las Glorias Navales

Chile naval and national civic commemoration

Chilean Navy

Sister Maria Hummel Day

Hummel art/collector community / remembrance of Sister Maria Innocentia (Berta) Hummel

The M.I. Hummel organization records Berta Hummel’s birth on 21 May 1909; an observance reference places Sister Maria Hummel Day on the same 21 May birthday anchor.

National Waiters Day

United Kingdom / hospitality front-of-house recognition campaign

Hospitality-industry coverage identifies National Waiters Day as a May 21 campaign inspired by Fred Sirieix and led by the Springboard Charity.

Harvey Milk Day

California, United States / day of special significance in education law

California Department of Education cites Education Code section 37222.13 designating May 22 of each year as Harvey Milk Day and encouraging educational remembrance

International Day for Biological Diversity

United Nations / Convention on Biological Diversity observance

A/RES/55/201

National Craft Distillery Day

United States / N Scott Distillery-created craft-distillery recognition observance

National Day Calendar identifies Nicholas Strauser, Connie Strauser and Brandy Strauser-Sobanski of N Scott Distillery as the 2019 founders and records May 22 as the annual observance date.

National Maritime Day

United States patriotic and national observance

United States Code, title 36 §128

National Vanilla Pudding Day

Informal food-calendar usage documented by Association of Nutrition & Foodservice Professionals chapter material

Two Association of Nutrition & Foodservice Professionals chapter calendars list National Vanilla Pudding Day on 22 May.

Commemoration of the abolition of slavery — Martinique

Martinique / statutory abolition commemoration and public holiday

French Labour Code article L3422-2 designates 22 May in Martinique as a public holiday for the commemoration of the abolition of slavery.

World Goth Day

international goth-culture celebration

World Goth Day organizers

World Preeclampsia Day

international preeclampsia awareness observance

Preeclampsia Foundation and global maternal-health partners

International Day to End Obstetric Fistula

United Nations / international observance

A/RES/67/147

World Turtle Day®

International / American Tortoise Rescue campaign

The official World Turtle Day site states that American Tortoise Rescue founded the observance in 2000 and that World Turtle Day is held annually on May 23; its 2026 release marks the 26th…

Aviation Maintenance Technician Day

United States aviation profession

The Federal Aviation Administration identifies May 24 as Aviation Maintenance Technician Day and describes it as an opportunity to recognize aviation maintenance technicians.

Bermuda Day

Bermuda public cultural celebration

Government of Bermuda

Ecuador's Independence Day

Ecuador

Australia’s Department of Foreign Affairs and Trade current National Days protocol register lists Ecuador — Ecuador's Independence Day on 24 May. The source verifies the diplomatic national…

Independence Day

Eritrea

Australia’s Department of Foreign Affairs and Trade current National Days protocol register lists Eritrea — Independence Day on 24 May. The source verifies the diplomatic national-day ident…

International Day of the Markhor

United Nations / international observance

A/RES/78/278

International Women’s Day for Peace and Disarmament

International feminist peace movement / WILPF

Women’s International League for Peace and Freedom states that pacifist feminists established 24 May as International Women’s Day for Peace and Disarmament in the early 1980s.

National Brother’s Day

United States / informal sibling-appreciation observance

National Today and Days Of The Year independently place the Brother’s Day observance on May 24; Days Of The Year explicitly records National Brothers Day and National Brother’s Day as alter…

National Caterers Appreciation Day

Workplace / catering staff appreciation observance

NHS Professionals’ 2026 awareness calendar lists National Caterers Appreciation Day on May 24, with calendar corroboration supporting the same date.

National Wyoming Day

United States / National Day Calendar National State Days series — Wyoming

National Day Calendar lists National Wyoming Day on 24 May. The U.S. Senate records Wyoming’s admission/statehood date as 10 July 1890. These are separate facts: the calendar listing is an…

African Liberation Day (African Day)

The Gambia / official holiday-list terminology

The official Government of The Gambia holiday list names May 25 as African Liberation Day (African Day).

Día de la Revolución de Mayo

Argentina / May Revolution national commemoration

Argentina’s national government identifies May 25 as Día de la Revolución de Mayo y Primer Gobierno Patrio and treats it as an immovable national holiday.

Geek Pride Day

Spain-origin / international geek-culture observance

Spanish press coverage documents May 25 as Día del Orgullo Friki/Geek Pride Day and traces the organized Spanish observance to 2006.

International Skin Pigmentation Day

International / Bella Aurora/Lullage brand-led skin-pigmentation awareness campaign

Bella Aurora’s own campaign pages document International Skin Pigmentation Day on May 25 across multiple editions, including 2021 and 2022.

Independence Day

Jordan

Australia’s Department of Foreign Affairs and Trade current National Days protocol register lists Jordan — Independence Day on 25 May. The source verifies the diplomatic national-day identi…

National Bath Bomb Day

United States / Desert Bath Company-created bath-product observance

National Day Archives records May 25 of each calendar year and identifies Desert Bath Company as the 2021 creator; current calendar coverage preserves the same date.

National Missing Children’s Day

United States / missing-children awareness

The National Center for Missing & Exploited Children states that May 25 is National Missing Children’s Day and explains that the first national observance was proclaimed in 1983 in memory o…

National VTuber Day

Online creator/fandom / Peter Lasalandra-created VTuber appreciation observance

National Day Archives records May 25 each calendar year and Peter Lasalandra as the creator in May 2021.

National Wine Day

Informal food-calendar usage documented by Association of Nutrition & Foodservice Professionals chapter material

Two Association of Nutrition & Foodservice Professionals chapter calendars list National Wine Day on 25 May.

World Football Day

United Nations / international observance

A/RES/78/281

World Thyroid Day

international thyroid-health awareness observance

European Thyroid Association and sister thyroid associations

Independence Day

Georgia

A 26 May 2026 ministry page explicitly documents Georgia’s Independence Day celebrations.

Guyana Independence Day

Guyana

The Organization of American States’ current country page lists Guyana National Independence Day as 26 May.

National Blueberry Cheesecake Day

United States / blueberry-industry observance

The U.S. Highbush Blueberry Council repeatedly identifies May 26 as National Blueberry Cheesecake Day in its industry marketing materials.

National Cherry Dessert Day

Informal food-calendar usage documented by Association of Nutrition & Foodservice Professionals chapter material

Two Association of Nutrition & Foodservice Professionals chapter calendars from different publication years list National Cherry Dessert Day on 26 May.

National Sorry Day

Australian national remembrance and reconciliation observance

Australian Government / Department of the Prime Minister and Cabinet

World Lindy Hop Day

global Lindy Hop dance, history and community observance

Frankie Manning Foundation

Commemoration of the abolition of slavery — Saint-Martin

Saint-Martin / statutory abolition commemoration and public holiday

French Labour Code article L3422-2 currently designates 27 May in Saint-Martin as a public holiday for the commemoration of the abolition of slavery.

Amateur Radio Military Appreciation Day

United States / ARMAD founder-led amateur-radio military appreciation event

ARMAD was founded by Emery McClendon in 2003. Contemporary ARMAD references place the annual event on the Saturday of U.S. Memorial Day weekend.

Emergency Medicine Day

Organizer-backed international observance

European Society for Emergency Medicine (EUSEM) and participating emergency-medicine organizations

Memorial Day

United States

The U.S. National Park Service explains that Congress established Memorial Day as a national holiday observed on the last Monday in May.

National Hairstylist Mental Health Awareness Day

United States / Booksy-created hairstylist mental-health awareness observance

Beauty-industry material published on May 27 states that Booksy designated May 27 as National Hairstylist Mental Health Awareness Day; current observance listings attribute the 2021 creatio…

National Italian Beef Day

United States / informal Buona-created Italian-beef promotion

Buona states that it coined/founded National Italian Beef Day in 2015 for the Saturday during U.S. Memorial Day weekend; its 2025 and 2026 releases place it on May 24 and May 23 respectivel…

Prayer for Peace, Memorial Day

United States / federal Memorial Day prayer proclamation framework

The Federal Register records the statutory proclamation framework for Prayer for Peace, Memorial Day and the annual Memorial Day observance; Memorial Day falls on the last Monday in May.

Commemoration of the abolition of slavery — Guadeloupe

Guadeloupe / statutory abolition commemoration and public holiday

French Labour Code article L3422-2 designates 27 May in Guadeloupe as a public holiday for the commemoration of the abolition of slavery.

Independence Day

Azerbaijan / national holiday

Azerbaijan’s 2021 law names 28 May Independence Day, commemorating the 1918 declaration by the Azerbaijan Democratic Republic; the presidential holiday register uses the current Independenc…

International Burger Day

International / informal burger-food observance

National Today gives International Burger Day a fixed May 28 recurrence, while McDonald’s India independently marks International Burger Day in a company post published on May 28.

International Day of Action for Women’s Health

International / WGNRR-coordinated health-rights campaign

The May 28 campaign site identifies 28 May as the International Day of Action for Women’s Health and states that the campaign is coordinated by the Women’s Global Network for Reproductive R…

Menstrual Hygiene Day

Organizer-backed global awareness and action day

WASH United / Menstrual Hygiene Day movement

National Day

Ethiopia

Australia’s Department of Foreign Affairs and Trade current National Days protocol register lists Ethiopia — National Day on 28 May.

National Flag Day / National Flag Days

Philippines / national flag commemoration

The Philippine Information Agency states that 28 May marks National Flag Day, declared by Presidential Proclamation No. 374 s. 1965, and that National Flag Days are observed from 28 May to…

National Hamburger Day

United States / informal food observance with repeated burger-brand usage

Wendy’s and BurgerFi first-party materials identify May 28 as National Hamburger Day in separate years.

Whooping Crane Day

North America / whooping-crane conservation awareness observance

Houston Zoo states that Whooping Crane Day takes place on May 28 each year, and the International Crane Foundation independently promoted Whooping Crane Day for May 28 in 2026.

World Hunger Day

global hunger awareness and action observance

World Hunger Day / The Hunger Project

World Passion Fruit Martini Day

International promotional/cocktail context / Funkin Cocktails-created observance

Current references place World Passion Fruit Martini Day on May 28 and attribute its establishment in 2021 to Funkin Cocktails.

International Day of UN Peacekeepers

United Nations / international observance

A/RES/57/129

International Sagarmatha (Mount Everest) Day

Nepal mountaineering and tourism commemoration of the first confirmed ascent of Everest

Nepal Tourism Board documents International Sagarmatha (Mount Everest) Day on 29 May, commemorating the 29 May 1953 ascent by Tenzing Norgay and Edmund Hillary.

National Alligator Day

Wild Florida-created wildlife education observance

Wild Florida says it created National Alligator Day on May 29 in 2021 to raise awareness and improve understanding of alligators and their ecosystem role.

IOSF World Otter Day

International / International Otter Survival Fund campaign

The International Otter Survival Fund states that it established IOSF World Otter Day and that it takes place on the last Wednesday in May each year.

International Day of Potato

FAO / United Nations / international observance

A/RES/78/123

National E-Bike Day

United States / Lectric eBikes-founded recognition day

Lectric eBikes and the Outdoor Industry Association identify May 30 as National E-Bike Day and attribute its establishment to Lectric.

World MS Day

Organizer-backed international awareness observance

MS International Federation (MSIF) and its members

European Neighbours’ Day

Europe / neighbourhood-solidarity initiative originating in Paris in 1999

European institutional and city-project sources describe European Neighbours’ Day as an annual event held on the last Friday of May, originating in Paris in 1999.

National Fisherfolks Day

Philippines / national fisherfolk-sector recognition

Philippine Proclamation No. 261 (2000) declares May 31 of every year as National Fisherfolks Day.

National Heat Awareness Day

United States / heat-safety awareness

A New York legislative resolution states that National Heat Awareness Day is observed each year on the last Friday in May to highlight heat-related health risks.

National Save Your Hearing Day

United States / hearing-loss prevention awareness observance

CDC/NIOSH explicitly identifies May 31 as National Save Your Hearing Day; longstanding professional materials also use the May 31 observance.

National Smile Day

Privately founded smile/dental-awareness observance

A founder-issued press release from Compassionate Dental Care states that Dr. Tim Stirneman and Jim Wojdyla founded National Smile Day on 31 May.

National Speak in Complete Sentences Day

United States / informal language observance

National Day Calendar and National Today independently place National Speak in Complete Sentences Day on May 31 each year.

National Utah Day

United States / National Day Calendar National State Days series — Utah

National Day Calendar lists National Utah Day on 31 May. The U.S. Senate records Utah’s admission/statehood date as 4 January 1896. These are separate facts: the calendar listing is an info…

Necrotizing Fasciitis Awareness Day

United States / awareness day repeatedly recognized by state proclamations

State government proclamations in multiple years designate May 31 as Necrotizing Fasciitis Awareness Day, supporting a recurring commemorative date while not making it a federal holiday.

World No Tobacco Day

WHO / international observance

WHA42.19

World Parrot Day

global parrot awareness and conservation observance

World Parrot Trust