2026
First observance
International Wellness Day
UN material marked International Wellness Day on 15 April 2026, the first annual date after the March 2026 proclamation.
Evergreen date guide
What is celebrated on April 15?
See the observances and verified observance-history milestones attached to April 15. 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.
2015
First observance
One Boston Day
The 2016 City account states that the prior year marked the beginning of the new annual Boston tradition.
2012
First observance
World Art Day
The International Association of Art states that it created World Art Day in 2012 and chose 15 April; its own newsletter archive identifies the 2012 launch as the first World Art…
2004
First observance
Jackie Robinson Day
MLB states that April 15 has been dedicated as Jackie Robinson Day each year since 2004; combined with the fixed April 15 recurrence, this supports the 2004 first annual edition.
Curated global anchors
See the collection →Major global guides on April 15
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
World Art Day
Reviewed depth
Other in-depth guides on April 15
Source-backedFixed AnnualIn-depth guide
Hari Perisytiharan Melaka Sebagai Bandaraya Bersejarah
Melaka state history records the Historical City declaration on 15 April 1989, while a Malaysian government calendar carries the proclamation-day observance on 15 April.
Source-backedFixed AnnualIn-depth guide
International Wellness Day
A/RES/80/249
Source-backedFixed AnnualIn-depth guide
Jackie Robinson Day
MLB states that every April 15 baseball honors Jackie Robinson’s legacy and that April 15 has been dedicated as Jackie Robinson Day each year since 2004; MLB also documented the 2026 league…
Source-backedEdition SpecificIn-depth guide
National American Sign Language Day
California’s disability-access commission and the American School for the Deaf corroborate recurring April 15 National ASL Day and the school’s April 15, 1817 opening; this is not an automa…
Source-backedFixed AnnualIn-depth guide
One Boston Day
City of Boston material documents the 2015 beginning of One Boston Day, a 2016 mayoral proclamation permanently designating April 15, and continuing City stewardship in 2026.
Source-backedFixed AnnualIn-depth guide
RMS Titanic sinking anniversary
NOAA verifies that RMS Titanic sank on 15 April 1912 and describes the protected wreck site as a memorial. The record is a historical anniversary and does not assert creation of a separatel…
Explore the mix
All topics →Topics represented on April 15
8 observances
All observances on this date
Source-backedFixed AnnualIn-depth guide
Hari Perisytiharan Melaka Sebagai Bandaraya Bersejarah
Melaka state history records the Historical City declaration on 15 April 1989, while a Malaysian government calendar carries the proclamation-day observance on 15 April.
Source-backedFixed AnnualIn-depth guide
International Wellness Day
A/RES/80/249
Source-backedFixed AnnualIn-depth guide
Jackie Robinson Day
MLB states that every April 15 baseball honors Jackie Robinson’s legacy and that April 15 has been dedicated as Jackie Robinson Day each year since 2004; MLB also documented the 2026 league…
Source-backedEdition SpecificIn-depth guide
National American Sign Language Day
California’s disability-access commission and the American School for the Deaf corroborate recurring April 15 National ASL Day and the school’s April 15, 1817 opening; this is not an automa…
Source-backedFixed AnnualIn-depth guide
One Boston Day
City of Boston material documents the 2015 beginning of One Boston Day, a 2016 mayoral proclamation permanently designating April 15, and continuing City stewardship in 2026.
Source-backedFixed AnnualIn-depth guide
RMS Titanic sinking anniversary
NOAA verifies that RMS Titanic sank on 15 April 1912 and describes the protected wreck site as a memorial. The record is a historical anniversary and does not assert creation of a separatel…
Source-backedFixed AnnualIn-depth guide
Universal Day of Culture under the Banner of Peace
Nicholas Roerich’s writings proposed a World/Universal Day of Culture, and the international movement dedicated to the initiative identifies 15 April as its observance.
Source-backedFixed AnnualIn-depth guide
World Art Day
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 →