2024
Evergreen date guide
What is celebrated on September 21?
See the observances and verified observance-history milestones attached to September 21. Each observance keeps its own source and date details.
Verified history
Today in history →On this date in observance history
Selected observance milestones connected to this date, based on reviewed sources.
2013
First observance
National Ladies Learning Code Day
Canada Learning Code states that the first Ladies Learning Code Day launched on September 21, 2013.
1998
Institutional decision
California Native American Day
California government historical material states that Governor Pete Wilson signed AB 1953 into law on 21 September 1998.
1998
Institutional decision
Native American Day (California)
California state historical materials identify September 21, 1998 as the signing date for the Native American Day law.
1981
First observance
Belize Independence Day
Belize government material identifies September 21, 1981 as the date the country gained independence; the project does not infer a separate earlier recurring observance.
1964
First observance
Independence Day
Government of Malta history refers to the 21 September 1964 independence date as Independence Day, and the current anniversary count is consistent with that inaugural observance.
Curated global anchors
See the collection →Major global guides on September 21
A reviewed starting point drawn from prominent global observances with strong institutional or organizer sources. Each observance keeps its own documented status and scope.
Source-backedFixed AnnualIn-depth guide
International Day of Peace
A/RES/36/67
Reviewed depth
Other in-depth guides on September 21
Source-backedFixed AnnualIn-depth guide
Armenia Independence Day
Armenia’s legal-information system records the 21 September 1991 independence referendum, the 24 September 1991 decision making September 21 a festive non-working day, and the current Holid…
Source-backedFixed AnnualIn-depth guide
Belize Independence Day
Belize government sources identify September 21, 1981 as the date of independence. The current public-holiday framework is separate: the Holidays Act makes scheduled days public holidays, a…
Source-backedFixed AnnualIn-depth guide
Independence Day
Malta government history states that Prime Minister George Borg Olivier set September 21 as Independence Day; UK legislation fixes 21 September 1964 as the independence transition and curre…
Source-backedFixed AnnualIn-depth guide
National Cat & Dog Gut Health Awareness Day
AnimalBiome documented celebrating Cat & Dog Gut Health Awareness Day on September 21, 2022 while launching its inaugural State of the Gut report. The Animal Medical Center independently li…
Source-backedFixed AnnualIn-depth guide
National Opioid Awareness Day
Indian Health Service identifies September 21 as National Opioid Awareness Day; Alabama Department of Mental Health calls September 21 an annual observance in 2025 and 2026. A separately do…
Source-backedRule Based AnnualIn-depth guide
Respect for the Aged Day (敬老の日)
Japan’s Cabinet Office explains that Respect for the Aged Day has fallen on the third Monday of September since 2003; in 2026 that is 21 September. It separately identifies 15 September as…
Explore the mix
All topics →Topics represented on September 21
7 observances
All observances on this date
Source-backedFixed AnnualIn-depth guide
Armenia Independence Day
Armenia’s legal-information system records the 21 September 1991 independence referendum, the 24 September 1991 decision making September 21 a festive non-working day, and the current Holid…
Source-backedFixed AnnualIn-depth guide
Belize Independence Day
Belize government sources identify September 21, 1981 as the date of independence. The current public-holiday framework is separate: the Holidays Act makes scheduled days public holidays, a…
Source-backedFixed AnnualIn-depth guide
Independence Day
Malta government history states that Prime Minister George Borg Olivier set September 21 as Independence Day; UK legislation fixes 21 September 1964 as the independence transition and curre…
Source-backedFixed AnnualIn-depth guide
International Day of Peace
A/RES/36/67
Source-backedFixed AnnualIn-depth guide
National Cat & Dog Gut Health Awareness Day
AnimalBiome documented celebrating Cat & Dog Gut Health Awareness Day on September 21, 2022 while launching its inaugural State of the Gut report. The Animal Medical Center independently li…
Source-backedFixed AnnualIn-depth guide
National Opioid Awareness Day
Indian Health Service identifies September 21 as National Opioid Awareness Day; Alabama Department of Mental Health calls September 21 an annual observance in 2025 and 2026. A separately do…
Source-backedRule Based AnnualIn-depth guide
Respect for the Aged Day (敬老の日)
Japan’s Cabinet Office explains that Respect for the Aged Day has fallen on the third Monday of September since 2003; in 2026 that is 21 September. It separately identifies 15 September as…
How dates are selected
This page combines fixed annual dates, reusable calendar rules and year-specific dates confirmed for 2026. Variable or historical dates are included only when they are clearly supported.
Read the methodology →