1995
First observance
National Newspaper Columnists Day
NSNC says it first marked the day in 1995, the 50th anniversary of Ernie Pyle’s death.
Evergreen date guide
What is celebrated on April 18?
See the observances and verified observance-history milestones attached to April 18. 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.
1982
First observance
International Day for Monuments and Sites
ICOMOS states that every 18 April has been celebrated as the International Day for Monuments and Sites since 1982 and describes the 18 April 1982 Hammamet meeting at which the ide…
1978
First observance
Education and Sharing Day, U.S.A.
Public Law 95-262 designates April 18, 1978 for the first federal layer reviewed here.
Reviewed depth
Other in-depth guides on April 18
Source-backedFixed AnnualIn-depth guide
International Day for Monuments and Sites
International Council on Monuments and Sites (ICOMOS)
Source-backedFixed AnnualIn-depth guide
National Animal Crackers Day
National Day Archives lists the canonical plural National Animal Crackers Day on April 18; the public singular title is retained as an alias.
Source-backedFixed AnnualIn-depth guide
National Exercise Day
National Day Archives lists National Exercise Day on April 18 and identifies Jeuse Saint-Fleur, DNP as its creator in 2020.
Source-backedFixed AnnualIn-depth guide
National Newspaper Columnists Day
National Society of Newspaper Columnists first-party history says the society passed a resolution establishing April 18 as National Columnists Day, first marked it in 1995, and chose the an…
Source-backedEdition SpecificIn-depth guide
Record Store Day
Record Store Day first-party sources say the event was conceived in 2007, first held on 19 April 2008, and is normally held on the third Saturday of April; organizer materials also document…
Source-backedEdition SpecificIn-depth guide
Superman Day
DC and Warner Bros. Discovery’s official 2026 material identifies April 18 as Superman Day, links the date to Superman’s Action Comics #1 debut, and describes a global fan celebration. Revi…
Explore the mix
All topics →Topics represented on April 18
8 observances
All observances on this date
Source-backedFixed AnnualIn-depth guide
International Day for Monuments and Sites
International Council on Monuments and Sites (ICOMOS)
Source-backedFixed AnnualIn-depth guide
National Animal Crackers Day
National Day Archives lists the canonical plural National Animal Crackers Day on April 18; the public singular title is retained as an alias.
Source-backedFixed AnnualIn-depth guide
National Exercise Day
National Day Archives lists National Exercise Day on April 18 and identifies Jeuse Saint-Fleur, DNP as its creator in 2020.
Source-backedFixed AnnualIn-depth guide
National Newspaper Columnists Day
National Society of Newspaper Columnists first-party history says the society passed a resolution establishing April 18 as National Columnists Day, first marked it in 1995, and chose the an…
Source-backedEdition SpecificIn-depth guide
Record Store Day
Record Store Day first-party sources say the event was conceived in 2007, first held on 19 April 2008, and is normally held on the third Saturday of April; organizer materials also document…
Source-backedEdition SpecificIn-depth guide
Superman Day
DC and Warner Bros. Discovery’s official 2026 material identifies April 18 as Superman Day, links the date to Superman’s Action Comics #1 debut, and describes a global fan celebration. Revi…
Source-backedFixed AnnualIn-depth guide
World Amateur Radio Day
The International Amateur Radio Union states that World Amateur Radio Day is celebrated every April 18, the anniversary of IARU’s formation in Paris in 1925. IARU Resolution 94-3 establishe…
Source-backedRule Based AnnualIn-depth guide
World Circus Day
The Fédération Mondiale du Cirque maintains World Circus Day on the third Saturday in April. Contemporaneous Federation press-release material identifies 17 April 2010 as the inaugural Worl…
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 →