2018
First observance
National Child Identity Theft Awareness Day
The launch announcement describes “this year” participation and specific campaign activity scheduled for September 1, 2018.
Evergreen date guide
What is celebrated on September 1?
See the observances and verified observance-history milestones attached to September 1. 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.
2014
First observance
World Letter Writing Day
The official launch history records World Letter Writing Day being launched on 1 September 2014 at Waverley College.
2014
Institutional decision
World Letter Writing Day
The public launch itself occurred on 1 September 2014; no separate earlier adoption instrument is asserted.
1992
First observance
National Wattle Day
Australian National Botanic Gardens material describes the 1992 formal national declaration and September 1 ceremony; earlier non-national Wattle Day traditions are preserved sepa…
1910
Precursor
National Wattle Day
Earlier Wattle Day traditions existed before the 1992 nationwide proclamation; the national instrument standardized September 1 throughout Australia.
Reviewed depth
Other in-depth guides on September 1
Source-backedFixed AnnualIn-depth guide
Building and Code Staff Appreciation Day
The City of Lodi states in its 2026 proclamation background that Building and Code Staff Appreciation Day is observed annually on September 1; EventGuide independently lists September 1 eac…
Source-backedFixed AnnualIn-depth guide
Constitution Day
Slovak law lists 1 September as Constitution Day of the Slovak Republic; parliamentary history ties the date to adoption of the Constitution on 1 September 1992, while current government gu…
Source-backedFixed AnnualIn-depth guide
Ginger Cat Appreciation Day
UPI identifies Chris Roy as the 2014 founder and September 1 as the annual date; Animal Medical Center calendars independently repeat the date across multiple years.
Source-backedFixed AnnualIn-depth guide
Independence Day of the Republic of Uzbekistan
A 2026 government page identifies 1 September as Independence Day of the Republic of Uzbekistan and describes it as the main national holiday.
Source-backedFixed AnnualIn-depth guide
National Child Identity Theft Awareness Day
Experian announced on August 27, 2018 that it was designating September 1 as Child Identity Theft Awareness Day and intended it to become an annual reminder; the campaign included September…
Source-backedFixed AnnualIn-depth guide
National Little Black Dress Day
The Black Heart Association currently describes National Little Black Dress Day as its signature awareness initiative, says it is observed annually on September 1, and states that the assoc…
Explore the mix
All topics →Topics represented on September 1
8 observances
All observances on this date
Source-backedFixed AnnualIn-depth guide
Building and Code Staff Appreciation Day
The City of Lodi states in its 2026 proclamation background that Building and Code Staff Appreciation Day is observed annually on September 1; EventGuide independently lists September 1 eac…
Source-backedFixed AnnualIn-depth guide
Constitution Day
Slovak law lists 1 September as Constitution Day of the Slovak Republic; parliamentary history ties the date to adoption of the Constitution on 1 September 1992, while current government gu…
Source-backedFixed AnnualIn-depth guide
Ginger Cat Appreciation Day
UPI identifies Chris Roy as the 2014 founder and September 1 as the annual date; Animal Medical Center calendars independently repeat the date across multiple years.
Source-backedFixed AnnualIn-depth guide
Independence Day of the Republic of Uzbekistan
A 2026 government page identifies 1 September as Independence Day of the Republic of Uzbekistan and describes it as the main national holiday.
Source-backedFixed AnnualIn-depth guide
National Child Identity Theft Awareness Day
Experian announced on August 27, 2018 that it was designating September 1 as Child Identity Theft Awareness Day and intended it to become an annual reminder; the campaign included September…
Source-backedFixed AnnualIn-depth guide
National Little Black Dress Day
The Black Heart Association currently describes National Little Black Dress Day as its signature awareness initiative, says it is observed annually on September 1, and states that the assoc…
Source-backedFixed AnnualIn-depth guide
National Wattle Day
The Australian Government states that 1 September is National Wattle Day and records that the observance was officially proclaimed on 23 June 1992; current 2026 government material continue…
Source-backedFixed AnnualIn-depth guide
World Letter Writing Day
World Letter Writing Day’s official site documents its launch on 1 September 2014 and continues to identify 1 September as the celebration date.
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 →