United Nations Day for South-South Cooperation2026 · Date · History · Messages · Quotes
A/RES/58/220
About United Nations Day for South-South Cooperation
United Nations Day for South-South Cooperation is observed on 12 September. It highlights cooperation among developing countries through the exchange of knowledge, skills, resources, technology and development solutions.
The Day was originally established for 19 December and later moved to 12 September, making its date history important to explain correctly.
Why United Nations Day for South-South Cooperation matters
South-South cooperation is intended to complement, not replace, North-South cooperation. It can include peer learning, technical cooperation, regional initiatives, trade, investment, capacity-building and joint approaches to development challenges.
The observance is closely tied to the Buenos Aires Plan of Action, a foundational 1978 framework for technical cooperation among developing countries.
History of United Nations Day for South-South Cooperation
On 23 December 2003, the General Assembly adopted A/RES/58/220 and declared 19 December the United Nations Day for South-South Cooperation.
The first United Nations Day for South-South Cooperation was marked on 19 December 2004.
On 22 December 2011, General Assembly decision A/DEC/66/550 changed the annual observance from 19 December to 12 September beginning in 2012.
The new date marks 12 September 1978, when the United Nations Conference on Technical Cooperation among Developing Countries adopted the Buenos Aires Plan of Action.
How the observance developed
This timeline uses documented milestones from reviewed sources. Missing stages are left out rather than guessed.
Buenos Aires Plan of Action for Promoting and Implementing Technical Cooperation among Developing Countries
The 1978 Plan of Action became the historical anchor for the observance and, from 2012, for its current 12 September date.
United Nations General Assembly
UN General Assembly resolution A/RES/58/220
First documented observance
The Secretary-General’s 19 December 2004 message explicitly calls it the first United Nations Day for South-South Cooperation.
Changed the annual observance from 19 December to 12 September beginning in 2012.
United Nations General Assembly · A/DEC/66/550
United Nations Office for South-South Cooperation (UNOSSC)
UNOSSC convenes and supports official United Nations Day for South-South Cooperation observances.
What the evidence establishes
Confirmed institutional roles and milestones are shown first. Details that could not be established from the reviewed sources are listed separately below.
2 fields not established in reviewed sources
Predecessor and precursor observances
Earlier or merged observances are kept separate from former names and later institutional actions.
Later institutional actions
Later recognition, renaming, mergers or date changes are kept separate from original establishment.
How to Observe United Nations Day for South-South Cooperation
Study a current South-South cooperation project and identify what knowledge, finance or technical capacity is being exchanged between partners.
Compare South-South and triangular cooperation while avoiding the assumption that one model substitutes for all other development partnerships.
Use official project evaluations to discuss results, limitations and whether knowledge transfer can be adapted to local contexts.
Trace how the Buenos Aires Plan of Action still influences present-day cooperation frameworks.
United Nations Day for South-South Cooperation Facts
The Day is now observed on 12 September.
A/RES/58/220 originally designated 19 December.
The first UN Day was marked on 19 December 2004.
A/DEC/66/550 changed the date to 12 September beginning in 2012.
The current date marks adoption of the Buenos Aires Plan of Action on 12 September 1978.
United Nations Day for South-South Cooperation Messages
On United Nations Day for South-South Cooperation, may informed participation, respectful dialogue and public responsibility strengthen the communities we share.
United Nations Day for South-South Cooperation is a reminder that civic life is strongest when people listen, learn and take part with care.
May United Nations Day for South-South Cooperation encourage thoughtful participation, respect for others and attention to the institutions that shape everyday life.
Marking United Nations Day for South-South Cooperation can begin with one useful step: learn the issue, hear different perspectives and take part constructively.
Wishing everyone observing United Nations Day for South-South Cooperation a day of informed reflection, respectful conversation and meaningful participation.
United Nations Day for South-South Cooperation Quotes
“South-South and triangular cooperation are engines of progress and vital to achieving the Sustainable Development Goals.”
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.
- Remembrance Civic Context Care.
Evidence & sources
Sources used across the guide are gathered here. Labels show how each source supports the page, and contextual references are kept separate from primary evidence.
United Nations Digital Library — A/DEC/66/550 (opens in a new tab)
United Nations Digital Library — A/RES/58/220 (opens in a new tab)
UN Secretary-General — first observance (opens in a new tab)
United Nations Office for South-South Cooperation (opens in a new tab)
United Nations — List of International Days and Weeks (opens in a new tab)
United Nations — Observances: who chooses them and how (opens in a new tab)
Understand it, compare it, then explore further
Start with the most common factual questions, then compare closely related observances and explore useful connections.
Frequently asked questions
When is United Nations Day for South-South Cooperation?
12 September The documented recurrence rule is: 12 September.
Does United Nations Day for South-South Cooperation fall on the same date every year?
Yes. It uses a fixed annual date unless stronger evidence changes the pattern.
Is United Nations Day for South-South Cooperation an official public holiday?
The reviewed sources verify 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 reliable evidence explicitly does so.
Who established or recognizes United Nations Day for South-South Cooperation?
The reviewed sources identify United Nations General Assembly as the proclaiming or establishing body. Current facilitation or coordination is recorded as United Nations Office for South-South Cooperation (UNOSSC).
Is United Nations Day for South-South Cooperation international or country-specific?
The documented scope is international or global: 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 information is checked against reviewed sources, including the date pattern, scope and institutional history. This page was checked on 2026-09-05.
Was the United Nations Day for South-South Cooperation always on 12 September?
No. The General Assembly originally declared 19 December as the Day. Decision A/DEC/66/550 changed it to 12 September beginning in 2012.
When was it first observed?
The Secretary-General described 19 December 2004 as the first United Nations Day for South-South Cooperation.
Why is it now observed on 12 September?
The date marks 12 September 1978, when the United Nations Conference on Technical Cooperation among Developing Countries adopted the Buenos Aires Plan of Action.
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