Cholangiocarcinoma Foundation materials state that from 2023 World Cholangiocarcinoma Day is the third Thursday of February; its 2026 materials identify 19 February.

Source-backedEdition Specific

World Cloud Security Day

3 April 2026 · Cybersecurity profession / ISC2-recognized 2026 awareness date

ISC2’s 3 April 2026 article explicitly states that the date marks World Cloud Security Day. The source verifies the 2026 edition but does not by itself establish a permanent recurrence rule…

Source-backedFixed AnnualIn-depth guide

World Conjoined Twins Day

24 November · United Nations / international observance

A/RES/78/313

Source-backedRule Based Annual

World COPD Day

Third Wednesday in November · Organizer-backed international observance

Global Initiative for Chronic Obstructive Lung Disease (GOLD)

Source-backedEdition Specific

World Day for Safety and Health at Work

28 April 2026 · International Labour Organization / global occupational safety campaign

The ILO identifies 28 April 2026 as the World Day for Safety and Health at Work. The existing page title is retained as a search alias, not the formal ILO name.

Source-backedFixed AnnualIn-depth guide

World Day for Safety and Health at Work

28 April · ILO / United Nations / international observance

ILO observance

Source-backedFixed AnnualIn-depth guide

World Day for the Prevention of and Healing from Child Sexual Exploitation, Abuse and Violence

18 November · United Nations / international observance

A/RES/77/8

Source-backedFixed AnnualIn-depth guide

World Diabetes Day

14 November · WHO / United Nations-recognized global health observance

A/RES/61/225

Source-backedEdition Specific

World Digestive Health Day

29 May; 29 May 2026 verified · International / World Gastroenterology Organisation campaign

The World Gastroenterology Organisation’s 2026 campaign page states that it celebrates World Digestive Health Day each year and identifies Friday, May 29, 2026 for the current campaign.

Source-backedFixed AnnualIn-depth guide

World Down Syndrome Day

21 March · United Nations international observance

A/RES/66/149

Source-backedFixed AnnualIn-depth guide

World Drowning Prevention Day

25 July · United Nations / World Health Organization observance

A/RES/75/273

Source-backedFixed AnnualIn-depth guide

World Duchenne Awareness Day

7 September · United Nations / international observance

A/RES/78/12

Source-backedFixed Annual

World Ego Awareness Day

11 May · 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.

Source-backedRule Based Annual

World First Aid Day

Second Saturday in September · Organizer-backed global first-aid awareness observance

International Federation of Red Cross and Red Crescent Societies (IFRC)

Source-backedFixed AnnualIn-depth guide

World Food Safety Day

7 June · FAO / WHO / United Nations / international observance

A/RES/73/250

Source-backedFixed Annual

World Glaucoma Day

12 March · international glaucoma awareness observance

World Glaucoma Association / World Glaucoma Week tradition

Source-backedFixed Annual

World Hand Hygiene Day

5 May · World Health Organization campaign

WHO SAVE LIVES: Clean Your Hands campaign

Source-backedFixed AnnualIn-depth guide

World Health Day

7 April · World Health Organization global health observance

WHA/A.2/Res.35

Source-backedFixed AnnualIn-depth guide

World Hearing Day

3 March · World Health Organization global health observance

Source-backedFixed Annual

World Heart Day

29 September · World Heart Federation global campaign

Source-backedFixed Annual

World Hemophilia Day

17 April · Organizer-backed international observance

World Federation of Hemophilia (WFH)

Source-backedFixed AnnualIn-depth guide

World Hepatitis Day

28 July · World Health Organization global health observance

WHO observance

Source-backedEdition Specific

World Homoeopathy Day

10 April; 2026 official Indian event ran 10–11 April · India / homoeopathy professional, education and regulatory community

India’s National Commission for Homoeopathy documents World Homoeopathy Day 2026 at Vigyan Bhawan on 10–11 April and related official activities.

Source-backedRule Based Annual

World Hospice and Palliative Care Day

Second Saturday in October; 10 October 2026 verified · International / WHPCA-coordinated palliative-care community

The Indian Association of Palliative Care reports that the 2026 World Hospice and Palliative Care Day is October 10 and that the WHPCA-coordinated observance is marked every second Saturday…

Source-backedFixed Annual

World Hypertension Day

17 May · Organizer-backed international observance

World Hypertension League (WHL)

Source-backedFixed Annual

World Hypnotism Day

4 January annually · International organizer-led awareness observance

The official World Hypnotism Day organization identifies 4 January as the observance and maintains current 2026 event information.

Source-backedFixed Annual

World IBD Day

19 May · Organizer-backed international observance

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

Source-backedEdition Specific

World Immunization Week

24–30 April 2026 · World Health Organization / global immunization campaign

WHO’s formal campaign is World Immunization Week, held 24–30 April; WHO lists the 2026 edition for 24–30 April 2026. The site’s “World Immunization Day” title is therefore a search alias, n…

Source-backedFixed Annual

World Immunization Week

24–30 April · World Health Organization global campaign

WHO campaign

Source-backedFixed Annual

World KC Day

10 November · keratoconus awareness and support observance

National Keratoconus Foundation (NKCF)

Source-backedRule Based Annual

World Kidney Day

Second Thursday in March · Organizer-backed international observance

International Society of Nephrology (ISN) and International Federation of Kidney Foundations – World Kidney Alliance (IFKF-WKA)

Source-backedRule Based Annual

World Leprosy Day

Last Sunday of January (30 January every year in India) · World Health Organization-supported observance

WHO campaign / global health observance

Source-backedEdition Specific

World Lung Cancer Day

1 August; 1 August 2026 verified · International respiratory-health community / ATS and partner societies

The American Thoracic Society and partner respiratory societies marked World Lung Cancer Day on August 1, 2026 in a current global awareness statement.

Source-backedFixed Annual

World Lupus Day

10 May · Organizer-backed international observance

World Lupus Federation and the global lupus community

Source-backedFixed AnnualIn-depth guide

World Malaria Day

25 April · World Health Organization global health observance

WHO observance

Source-backedFixed Annual

World Meningitis Day

5 October · WHO-supported global health awareness observance

World Health Organization — Defeating Meningitis by 2030 framework and awareness platform

Source-backedFixed Annual

World Menopause Day

18 October · Organizer-backed global health awareness observance

International Menopause Society (IMS)

Source-backedFixed AnnualIn-depth guide

World Mental Health Day

10 October · Global mental-health observance

WHO observance

Source-backedFixed Annual

World Mosquito Day

20 August · mosquito-borne disease history and awareness observance

London School of Hygiene & Tropical Medicine historical-source verification

Source-backedFixed Annual

World MS Day

30 May · Organizer-backed international awareness observance

MS International Federation (MSIF) and its members

Source-backedFixed Annual

World Narcissistic Abuse Awareness Day

1 June annually · Global / WNAAD organizer-led awareness campaign

The World Narcissistic Abuse Awareness Day organization identifies 1 June as the annual awareness date and says the initiative was established in 2016.

Source-backedFixed AnnualIn-depth guide

World Neglected Tropical Diseases Day

30 January · World Health Organization official global public-health day

Source-backedFixed Annual

World NF Awareness Day

17 May annually · 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.

Source-backedFixed AnnualIn-depth guide

World No Tobacco Day

31 May · WHO / international observance

WHA42.19

Source-backedFixed Annual

World Obesity Day

4 March · Global campaign convened by World Obesity Federation

Source-backedFixed Annual

World Oral Health Day

20 March · Organizer-backed international observance

FDI World Dental Federation

Source-backedFixed Annual

World Osteoporosis Day

20 October · Organizer-backed international health awareness observance

International Osteoporosis Foundation (IOF)

Source-backedFixed Annual

World Ovarian Cancer Day

8 May annually · 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.

Source-backedRule Based Annual

World Pancreatic Cancer Day

Third Thursday in November; 19 November 2026 verified · International / World Pancreatic Cancer Coalition network

Pancreatic Cancer UK, a World Pancreatic Cancer Coalition member and steering-committee participant, states that World Pancreatic Cancer Day typically falls on the third Thursday of Novembe…

Source-backedFixed Annual

World Parkinson's Day

11 April · Organizer-backed international observance

Parkinson's Europe and the international Parkinson’s community

Source-backedFixed AnnualIn-depth guide

World Patient Safety Day

17 September · World Health Organization global health observance

WHO observance

Source-backedFixed Annual

World Pediatric Bone and Joint Day

19 October each year · United States Bone and Joint Initiative / pediatric musculoskeletal awareness

The United States Bone and Joint Initiative identifies 19 October as World Pediatric Bone and Joint Day in its awareness materials

Source-backedFixed Annual

World Pest Day

6 June · international professional pest-management awareness observance

Global pest-management associations; public-facing information hosted by the National Pest Management Association

Source-backedFixed Annual

World Pneumonia Day

12 November · Organizer-backed global health advocacy observance

Every Breath Counts coalition and global pneumonia community

Source-backedFixed Annual

World Polio Day

24 October · Organizer-backed global eradication awareness observance

Rotary International

Source-backedFixed Annual

World Pollution Prevention Day

2 December · International / informal environmental-awareness observance

National Today and EventGuide independently place World Pollution Prevention Day on December 2 each year.

Source-backedFixed Annual

World Preeclampsia Day

22 May · international preeclampsia awareness observance

Preeclampsia Foundation and global maternal-health partners

Source-backedFixed Annual

World Prematurity Day

15 November · World Health Organization official global health day

Source-backedFixed Annual

World Psoriasis Day

29 October · Organizer-backed international observance

International Federation of Psoriasis Associations (IFPA)

Source-backedFixed Annual

World Rabies Day

28 September · World Health Organization-supported observance

WHO global health observance

Source-backedFixed Annual

World Reef Day

1 June annually · Global / World Reef Day organizer-led awareness campaign

World Reef Day’s official materials identify 1 June as the recurring annual date and use the current campaign name World Reef Day.

Source-backedEdition Specific

World Schizophrenia Day

24 May 2026 in the cited organizer programme · International / schizophrenia awareness advocacy

The Schizophrenia Awareness Association’s current event page identifies World Schizophrenia Day 2026 on 24 May.

Source-backedFixed Annual

World Semicolon Day

16 April · mental-health awareness and resilience observance

Project Semicolon

Source-backedFixed Annual

World Sepsis Day

13 September · Organizer-backed international observance

Global Sepsis Alliance (GSA)

Source-backedFixed Annual

World Sexual Health Day

4 September · Organizer-backed global sexual-health awareness observance

World Association for Sexual Health (WAS)

Source-backedFixed AnnualIn-depth guide

World Sickle Cell Day

19 June · UN General Assembly resolution-backed awareness observance

United Nations General Assembly resolution A/RES/63/237

Source-backedRule Based Annual

World Sight Day

Second Thursday in October · Organizer-backed international observance

International Agency for the Prevention of Blindness (IAPB) and the global eye-health community

Source-backedFixed Annual

World Sjögren’s Day

23 July · Organizer-backed global health awareness observance

Sjögren’s Foundation

Source-backedVariable Custom

World Sleep Day

Friday before the March equinox · Organizer-backed international observance

World Sleep Society

Source-backedFixed Annual

World Spina Bifida and Hydrocephalus Day

25 October · Organizer-backed international observance

International Federation for Spina Bifida and Hydrocephalus (IF)