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Evergreen date guide

What is celebrated on September 15?

For 2026, these source-backed observances resolve to Tuesday, September 15. Recurring rules can move in another year, so each record keeps its own date logic.

Date authority profile

What this date contains

14 unique authority records

The list is deduplicated at the public entity layer while retaining all research provenance behind each page.

0 stable or rule-calculated

0 fixed annual and 0 reusable rule-based records can be placed without inventing a new date.

0 edition-specific

Edition-specific dates appear only when the requested year matches the verified edition; variable and historical records remain gated.

8 explicit country-scope records

Country scope stays attached to the underlying record instead of being generalized into a worldwide observance.

1 reviewed in-depth guides

These entities add reviewed meaning, history, activities, facts and FAQs without rewriting the authority facts.

Reviewed depth

Other in-depth guides on September 15

Explore the mix

Topics represented on September 15

All topics →
Civic, Remembrance & History 6Community, Causes & Advocacy 4Food, Drink & Hospitality 2Workplace, Professions & Appreciation 1Health, Wellness & Awareness 1
14 date-resolved records

All observances on this date

Source-backedRule Based Annual

Get Ready Day

Third Tuesday in September; 15 September in 2026 · American Public Health Association / emergency preparedness

APHA places Get Ready Day on the third Tuesday in September as part of its preparedness initiative

Source-backedFixed Annual

Grito de Independencia / Grito de Dolores

15 September ceremony, preceding Mexico’s Independence Day on 16 September · Mexico; national independence commemoration tradition

Government of Mexico material describes the Grito de Independencia ceremony on 15 September, commemorating the historical call associated with the start of independence.

Source-backedFixed Annual

Independence Day

15 September · Costa Rica

Australia’s Department of Foreign Affairs and Trade current National Days protocol register lists Costa Rica — Independence Day on 15 September. The source verifies the diplomatic national-…

Source-backedFixed Annual

Independence Day

15 September · El Salvador

Australia’s Department of Foreign Affairs and Trade current National Days protocol register lists El Salvador — Independence Day on 15 September. The source verifies the diplomatic national…

Source-backedFixed Annual

Independence Day

15 September · Guatemala

Australia’s Department of Foreign Affairs and Trade current National Days protocol register lists Guatemala — Independence Day on 15 September. The source verifies the diplomatic national-d…

Source-backedFixed Annual

Independence Day

15 September · Honduras

Australia’s Department of Foreign Affairs and Trade current National Days protocol register lists Honduras — Independence Day on 15 September. The source verifies the diplomatic national-da…

Source-backedRule Based Annual

IT Professionals Day / IT Pro Day

Third Tuesday in September; 15 September 2026 · SolarWinds-created technology-professional appreciation observance

SolarWinds says IT Professionals Day was established in 2015 and is celebrated on the third Tuesday of each September.

Source-backedFixed Annual

National Africa Civility Day

15 September · Africa-focused / World Civility Presidential Club-created humanitarian recognition observance

National Day Archives records September 15 and credits World Civility Presidential Club with founding the observance in 2020; current awareness calendars retain September 15.

Source-backedFixed Annual

National Cheese Toast Day

15 September · United States / Sizzler-created branded food observance

Sizzler’s own press releases celebrate National Cheese Toast Day on September 15 and identify the chain’s participation in the observance.

Source-backedFixed Annual

National Double Cheeseburger Day

15 September · United States / informal food observance

Independent observance calendars identify September 15 as National Double Cheeseburger Day.

Source-backedFixed Annual

National Online Learning Day

15 September · United States / online-learning community observance registered in 2016

National Day Calendar states the observance was established in 2016 and proclaimed for September 15 annually; universities continue to recognize the same date.

Source-backedFixed Annual

National Tackle Kids Cancer Day

15 September · United States / Tackle Kids Cancer and Hackensack University Medical Center Foundation recognition

National Day Calendar records September 15 as the annual observance, beginning in 2017, and identifies Hackensack University Medical Center Foundation as the founder.

Source-backedFixed Annual

World Afro Day

15 September · global Afro-hair celebration, education and anti-discrimination observance

World Afro Day organization; first event endorsed by the UN Office of the High Commissioner for Human Rights

How this date is built

This page is assembled from verified fixed dates, reusable recurrence rules, and target-year records whose edition matches 2026. Variable, historical or unresolved records are not silently forced onto this date.

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