2025
Later action
Victory Day
An additional government holiday was declared immediately before Victory Day to provide uninterrupted leave because Victory Day itself was observed as a public holiday.
Evergreen date guide
What is celebrated on October 23?
See the observances and verified observance-history milestones attached to October 23. 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.
2017
First observance
National Croc Day
Crocs’ 2022 corporate history explicitly traces the fan-originated movement to October 23, 2017.
2017
Precursor
National Croc Day
Crocs fans used the pre-existing crocodile-day date as an opportunity to celebrate Crocs footwear; Crocs says Croc Day emerged from that fan activity.
2014
Precursor
International Day of the Snow Leopard
Snow-leopard range countries began celebrating 23 October as International Snow Leopard Day after the 2013 Bishkek Declaration. The United Nations later proclaimed an Internationa…
1991
First observance
Mole Day
Royal Society of Chemistry education material identifies 1991 as the first Mole Day celebration, consistent with Foundation history.
1989
Later action
23 October national holiday
The proclamation added a later constitutional milestone to the same calendar date.
1919
Institutional decision
Jura de la Constitución
IMPO records Law No. 6997 as promulgated on 23 October 1919.
1919
Institutional decision
Natalicio de José Gervasio Artigas
IMPO gives 23 October 1919 as the promulgation date of Law No. 6997.
Reviewed depth
Other in-depth guides on October 23
Source-backedFixed AnnualIn-depth guide
23 October national holiday
Hungary’s Fundamental Law names 23 October as a national holiday commemorating the 1956 Revolution and War of Independence. Government historical material also notes the proclamation of the…
Source-backedRule Based AnnualIn-depth guide
Champagne Day
The official Champagne site lists Champagne Day 2026 for October 23 and states that it takes place on the fourth Friday in October.
Source-backedFixed AnnualIn-depth guide
International Day of the Snow Leopard
A/RES/79/143
Source-backedFixed AnnualIn-depth guide
King Chulalongkorn Memorial Day (Piyamararaj Day)
Thailand Ministry of Foreign Affairs
Source-backedFixed AnnualIn-depth guide
Mole Day
The National Mole Day Foundation observes Mole Day on October 23 from 6:02 a.m. to 6:02 p.m., using the 6.02 × 10^23 notation for the Avogadro constant as the date-and-time mnemonic; its hi…
Source-backedFixed AnnualIn-depth guide
National Croc Day
Crocs corporate history traces Croc Day to fan activity on October 23, 2017 and repeatedly identifies October 23 as the annual Croc Day date, including in 2025. The inherited October 25 val…
Explore the mix
All topics →Topics represented on October 23
6 observances
All observances on this date
Source-backedFixed AnnualIn-depth guide
23 October national holiday
Hungary’s Fundamental Law names 23 October as a national holiday commemorating the 1956 Revolution and War of Independence. Government historical material also notes the proclamation of the…
Source-backedRule Based AnnualIn-depth guide
Champagne Day
The official Champagne site lists Champagne Day 2026 for October 23 and states that it takes place on the fourth Friday in October.
Source-backedFixed AnnualIn-depth guide
International Day of the Snow Leopard
A/RES/79/143
Source-backedFixed AnnualIn-depth guide
King Chulalongkorn Memorial Day (Piyamararaj Day)
Thailand Ministry of Foreign Affairs
Source-backedFixed AnnualIn-depth guide
Mole Day
The National Mole Day Foundation observes Mole Day on October 23 from 6:02 a.m. to 6:02 p.m., using the 6.02 × 10^23 notation for the Avogadro constant as the date-and-time mnemonic; its hi…
Source-backedFixed AnnualIn-depth guide
National Croc Day
Crocs corporate history traces Croc Day to fan activity on October 23, 2017 and repeatedly identifies October 23 as the annual Croc Day date, including in 2025. The inherited October 25 val…
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 →