Endangered Species Day2026 · Date · History
GovInfo records the U.S. Senate’s agreed S. Res. 431 designating May 11, 2006 as Endangered Species Day. Current U.S. Fish & Wildlife Service and Endangered Species Coalition material support continuing annual observance on the third Friday in May.
About Endangered Species Day
Endangered Species Day is an annual conservation-awareness observance now held on the third Friday in May.
The U.S. Senate agreed to S. Res. 431 in 2006 designating May 11, 2006 as Endangered Species Day, and current federal/conservation organizations continue to mark the day.
Why Endangered Species Day matters
The day focuses attention on threatened and endangered species, recovery work, habitat and conservation education.
Responsible participation should not expose sensitive wildlife locations, encourage handling of wild animals or reduce complex conservation status to unsourced universal claims.
History of Endangered Species Day
In 2006, Senator Dianne Feinstein sponsored S. Res. 431, which the Senate considered and agreed to, designating May 11, 2006 as Endangered Species Day.
Later Senate resolutions continued the designation in subsequent years.
Current U.S. Fish & Wildlife Service and Endangered Species Coalition material uses the third Friday in May; the Coalition describes 2026 as the 21st annual observance, consistent with a 2006 beginning.
How the observance developed
This timeline uses documented milestones from reviewed sources. Missing stages are left out rather than guessed.
Senator Dianne Feinstein
GovInfo identifies Senator Dianne Feinstein as sponsor of S. Res. 431.
United States Senate
S. Res. 431, 109th Congress
First documented observance
S. Res. 431 designated May 11, 2006, and current organizer history treats 2006 as the beginning of the annual observance.
The modern recurring observance is held on the third Friday in May rather than preserving May 11 as a fixed annual date.
Current Endangered Species Day organizers and supporting agencies · current annual observance practice
Endangered Species Coalition
Current first-party organizer material maintains the annual Endangered Species Day program; federal wildlife agencies also participate/support education.
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
Later institutional actions
Later recognition, renaming, mergers or date changes are kept separate from original establishment.
How to Observe Endangered Species Day
Learn about species from current agency or conservation-program sources and distinguish federal listing status from broader conservation categories.
Do not post precise locations of vulnerable wildlife, nests or dens when doing so could increase disturbance or exploitation risk.
Observe wildlife from an appropriate distance and follow site-specific rules rather than encouraging capture, feeding or handling.
Avoid claiming that every population of a species is increasing or declining unless the source is population-specific and current.
Endangered Species Day Facts
The first federal Endangered Species Day designation reviewed here was May 11, 2006.
S. Res. 431 was sponsored by Senator Dianne Feinstein and agreed to by the Senate.
Current observance guidance uses the third Friday in May.
The Endangered Species Coalition is a current primary organizer/sponsor, while federal wildlife agencies also support observance and education.
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.
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.
GovInfo — S. Res. 431, 109th Congress
U.S. Fish & Wildlife Service — current conservation observance material
Endangered Species Coalition — current Endangered Species Day program
Endangered Species Coalition — Endangered Species Day (opens in a new tab)
Conservation Organization
GovInfo — S. Res. 431, agreed to Senate (2006) (opens in a new tab)
Congressional Resolution
U.S. Fish & Wildlife Service — Endangered Species Day (opens in a new tab)
Federal Agency Conservation Observance
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 Endangered Species Day?
Third Friday in May The documented recurrence rule is: Third Friday in May.
Does Endangered Species Day fall on the same date every year?
It follows a recurring calendar rule, so the Gregorian date can change from year to year.
Is Endangered Species Day an official public holiday?
The reviewed sources verify it within this scope: United States conservation awareness 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 Endangered Species Day?
The reviewed sources identify United States Senate as the proclaiming or establishing body. The proposer or originator is recorded separately as Senator Dianne Feinstein. Current facilitation or coordination is recorded as Endangered Species Coalition.
Is Endangered Species Day international or country-specific?
No single country is assigned to this observance. Its documented scope is: United States conservation awareness observance. Use that scope rather than assuming worldwide or country-specific status.
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 2026-09-25.
When is Endangered Species Day?
It is currently observed on the third Friday in May.
When did it begin?
The U.S. Senate agreed to S. Res. 431 designating May 11, 2006 as Endangered Species Day; current organizer material describes 2026 as the 21st annual observance.
Who sponsored the first Senate resolution?
Senator Dianne Feinstein sponsored S. Res. 431, with multiple cosponsors.
How can people participate safely?
Use current conservation guidance, avoid disturbing or handling wildlife, and do not publish sensitive locations that could put vulnerable species at risk.
Other observances on May 21
These observances are also listed on May 21, 2027.
Bike to Work Day
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.
Día de las Glorias Navales
Chilean Navy
International Tea Day
A/RES/74/241
International Virtual Assistants Day
The original 2006 announcement and later OIVAC materials describe International Virtual Assistants Day as the third Friday of May each year.
National Defense Transportation Day
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 Waiters and Waitresses Day
Bar & Restaurant identifies May 21 as National Waiters and Waitresses Day in a dedicated 2014 article and in multiple hospitality promotional calendars.