World Down Syndrome Day
A/RES/66/149
A/RES/66/149
This authority record treats the observance as a fixed annual date. The same month and day can be reused unless a stronger source changes the rule. Public-holiday or government status is never inferred from the observance name alone.
Overview
World Down Syndrome Day is a United Nations observance on 21 March that promotes awareness, inclusion and the rights and participation of people with Down syndrome.
The day is most useful when people with Down syndrome are represented as participants, advocates and decision-makers rather than treated only as subjects of medical information.
Why it matters
Down syndrome is a naturally occurring chromosomal arrangement. People with Down syndrome have diverse lives, abilities, needs and preferences, so respectful coverage should avoid stereotypes and one-size-fits-all assumptions.
The observance connects awareness with inclusion in education, health care, work, community life and decision-making. Where possible, first-person perspectives should be centred.
History
World Down Syndrome Day activity predates its United Nations status. Down Syndrome International records that the World Down Syndrome Day website was hosted on its behalf from 2006 to 2010 so global activities could be recorded, followed by an international campaign for UN recognition.
On 19 December 2011, the UN General Assembly adopted resolution A/RES/66/149 and designated 21 March as World Down Syndrome Day, with annual United Nations observance beginning in 2012.
The date 21 March, written 21/3, was chosen to symbolize the three copies of chromosome 21 associated with Down syndrome. Down Syndrome International continues to coordinate World Down Syndrome Day activity with partner organizations.
How the observance developed
This timeline is assembled only from verified provenance fields. Missing stages are omitted rather than inferred.
Pre-UN World Down Syndrome Day campaign and global activity network
Down Syndrome International and partner organizations supported global World Down Syndrome Day activity before the General Assembly designated 21 March as a United Nations observance in December 2011, effective from 2012.
United Nations General Assembly
UN General Assembly resolution 66/149
First documented observance
The resolution called for annual observance beginning in 2012 and invited States, UN organizations and civil society to raise public awareness.
Down Syndrome International (DSi), in collaboration with partner organizations
The official World Down Syndrome Day site states that the website and associated activities are coordinated by Down Syndrome International in collaboration with partner organizations.
What the evidence establishes
Verified institutional roles and milestones are shown first. Fields that the reviewed sources do not establish remain fail-closed and are available below without competing with the confirmed record.
3 fields not established in reviewed sources
Predecessor and precursor observances
Earlier or merged observances are kept separate from former names and later institutional actions.
Ways to observe
Invite people with Down syndrome and representative organizations to shape events and content rather than speaking about them without participation.
Audit an activity, school, workplace or website for accessibility and practical inclusion barriers.
Use first-person stories only with informed consent and avoid reducing a person to a diagnosis.
Discuss inclusive education, employment, health care or independent living using current rights-based sources.
Correct stereotypes and outdated language using guidance from disability organizations and the UN.
Useful facts
World Down Syndrome Day is observed on 21 March.
World Down Syndrome Day activity was organized internationally before the day entered the UN calendar in 2012.
The UN General Assembly designated the day in 2011 through resolution A/RES/66/149.
21 March (21/3) symbolizes three copies of chromosome 21.
Down Syndrome International coordinates World Down Syndrome Day activity with partner organizations.
Topic and context
What this page does not assume
- Keep the source-defined country, community, organizer or institutional scope; do not silently broaden it.
- Do not treat the title alone as proof of government recognition or public-holiday status.
- Do not add a creator, founding story or origin claim unless the supporting evidence establishes it.
- Health Information Not Medical Advice.
Evidence & sources
Repeated links from the authority record, institutional provenance and editorial guide research are consolidated here. Badges show how each source is used; a contextual source is never treated as proof of establishment on its own.
United Nations Digital Library — A/RES/66/149 (opens in a new tab)
United Nations Enable — World Down Syndrome Day (opens in a new tab)
United Nations — World Down Syndrome Day (opens in a new tab)
Dedicated Authoritative Page
World Down Syndrome Day / Down Syndrome International — About WDSD and history (opens in a new tab)
Understand it, compare it, then explore further
Start with the most common factual questions, then use reviewed distinctions and related authority records to understand where this observance fits.
Frequently asked questions
When is World Down Syndrome Day?
21 March The stored recurrence guidance is: 21 March.
Does World Down Syndrome Day fall on the same date every year?
The authority record classifies it as fixed annual, so its month and day are reusable unless stronger evidence changes the rule.
Is World Down Syndrome Day an official public holiday?
The authority record verifies it within this scope: United Nations international observance. That recognition does not by itself make it a statutory public holiday; the site only makes public-holiday claims when the supporting authority record explicitly does so.
Who established or recognizes World Down Syndrome Day?
The reviewed provenance layer identifies United Nations General Assembly as the proclaiming or establishing body. Current facilitation or coordination is recorded as Down Syndrome International (DSi), in collaboration with partner organizations.
Is World Down Syndrome Day international or country-specific?
The record has international or global institutional scope: United Nations international observance. That does not mean every country treats the date as a public holiday or observes it in the same way.
How is this page verified?
The factual layer is source-backed and keeps its date rule, scope, provenance and editorial guardrails attached to the authority record. This record was checked on 2026-09-05.
When did World Down Syndrome Day become a UN observance?
The UN General Assembly designated the day in December 2011, with annual observance beginning in 2012.
Is World Down Syndrome Day the same as the International Day of Persons with Disabilities?
No. World Down Syndrome Day focuses specifically on Down syndrome on 21 March; the 3 December observance covers disability inclusion much more broadly.
What is the best way to include people with Down syndrome in observance content?
Include people with Down syndrome in planning, representation and decision-making, and use consent-based first-person perspectives where possible.
How this differs from closely related observances
These distinctions are separately reviewed and source-backed. They clarify scope; they do not change either authority record.
Is World Down Syndrome Day the same as International Day of Persons with Disabilities?
World Down Syndrome Day focuses specifically on Down syndrome, inclusion and the rights and participation of people with Down syndrome. The 3 December International Day of Persons with Disabilities covers disability inclusion much more broadly.
Open International Day of Persons with Disabilities →Distinction sources
Other observances on March 21
These records also resolve to March 21, 2027 under the current authority data.
California Strawberry Day
Two Association of Nutrition & Foodservice Professionals chapter calendars from different publication years list California Strawberry Day on 21 March.
Harmony Day
Department of the Prime Minister and Cabinet, Australian Government
Human Rights Day
The South African Government’s public-holidays page lists Human Rights Day on 21 March.
Independence Day
Australia’s Department of Foreign Affairs and Trade current National Days protocol register lists Namibia — Independence Day on 21 March. The source verifies the diplomatic national-day ide…
International Colour Day
International Colour Association (AIC)
International Day for the Elimination of Racial Discrimination
A/RES/2142 (XXI)