2012
Evergreen date guide
What is celebrated on April 10?
See the observances and verified observance-history milestones attached to April 10. 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.
2012
Institutional decision
Western Australia Day
The official legislation page records Royal Assent on 10 April 2012.
2012
Later action
Western Australia Day
Renamed Foundation Day as Western Australia Day while retaining the public-holiday framework.
2007
Institutional decision
Apolinario Mabini Day
Republic Act No. 9430 states that it was approved on April 10, 2007.
1995
First observance
National Siblings Day
The foundation timeline says Siblings Day began in 1995, and its current history identifies the observance as annual on April 10 from that founding.
1872
Reviewed depth
Other in-depth guides on April 10
Source-backedFixed AnnualIn-depth guide
Birth anniversary of Manlilikha ng Bayan Masino Intaray
The DILG Aurora advocacy calendar lists the birth anniversary of Manlilikha ng Bayan Masino Intaray on April 10 and gives 1943 as the birth year.
Source-backedRule Based AnnualIn-depth guide
National Donate Life Blue & Green Day
Donate Life America states National Donate Life Blue & Green Day is observed on the second Friday of April each year; New York State health authorities documented the April 10, 2026 observa…
Source-backedFixed AnnualIn-depth guide
National Encourage a Young Writer Day
New York Senate resolutions for both 2021 and 2022 recognize April 10 in conjunction with the observance of National Encourage a Young Writer Day, independently confirming the recurring mon…
Source-backedFixed AnnualIn-depth guide
National Farm Animals Day
Observance and historical-society sources identify April 10 as National Farm Animals Day and trace its creation to Colleen Paige in 2005.
Source-backedRule Based AnnualIn-depth guide
National Fast and Prayer Day
Liberian government sources tie the second-Friday-in-April national holiday to an 1883 Act, identify the current legal framework, and document continuing presidential proclamation practice…
Source-backedFixed AnnualIn-depth guide
National Report IRS Tax Fraud Day
The Hesch Firm’s contemporaneous April 5, 2018 announcement identifies Joel D. Hesch as creator and April 10 as the observance date; current IRS sources provide the authoritative reporting…
Explore the mix
All topics →Topics represented on April 10
8 observances
All observances on this date
Source-backedFixed AnnualIn-depth guide
Birth anniversary of Manlilikha ng Bayan Masino Intaray
The DILG Aurora advocacy calendar lists the birth anniversary of Manlilikha ng Bayan Masino Intaray on April 10 and gives 1943 as the birth year.
Source-backedRule Based AnnualIn-depth guide
National Donate Life Blue & Green Day
Donate Life America states National Donate Life Blue & Green Day is observed on the second Friday of April each year; New York State health authorities documented the April 10, 2026 observa…
Source-backedFixed AnnualIn-depth guide
National Encourage a Young Writer Day
New York Senate resolutions for both 2021 and 2022 recognize April 10 in conjunction with the observance of National Encourage a Young Writer Day, independently confirming the recurring mon…
Source-backedFixed AnnualIn-depth guide
National Farm Animals Day
Observance and historical-society sources identify April 10 as National Farm Animals Day and trace its creation to Colleen Paige in 2005.
Source-backedRule Based AnnualIn-depth guide
National Fast and Prayer Day
Liberian government sources tie the second-Friday-in-April national holiday to an 1883 Act, identify the current legal framework, and document continuing presidential proclamation practice…
Source-backedFixed AnnualIn-depth guide
National Report IRS Tax Fraud Day
The Hesch Firm’s contemporaneous April 5, 2018 announcement identifies Joel D. Hesch as creator and April 10 as the observance date; current IRS sources provide the authoritative reporting…
Source-backedFixed AnnualIn-depth guide
National Siblings Day
The Siblings Day Foundation states that its mission since 1995 has included establishing National Siblings Day annually on 10 April.
Source-backedFixed AnnualIn-depth guide
Walter Hunt safety-pin patent anniversary
The original U.S. Patent No. 6,281 text identifies Walter Hunt’s dress-pin invention and dates the patent 10 April 1849; Smithsonian collections also identify Hunt with the safety-pin inven…
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 →