2021
First observance
National Borinqueneers Day
U.S. Army reporting from Fort Buchanan explicitly describes April 13, 2021 as the first National Borinqueneers Day.
Evergreen date guide
What is celebrated on April 13?
See the observances and verified observance-history milestones attached to April 13. 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.
2016
First observance
National Make Lunch Count Day
The contemporaneous launch announcement invited workers to National Make Lunch Count Day on April 13, 2016.
1988
Later action
Feast Day of the Flemish Community
Replaced the 1973 symbols decree while retaining the Flemish Community feast-day framework.
1938
First observance
Thomas Jefferson's birthday
The 1938 proclamation called for observance on April 13, 1938 and each succeeding April 13.
Reviewed depth
Other in-depth guides on April 13
Source-backedFixed AnnualIn-depth guide
International FND Awareness Day
FND Hope International documents recurring International FND Awareness Day campaigns on 13 April, including the fifth annual edition in 2017 and sixth annual edition in 2018; current FND Ho…
Source-backedFixed AnnualIn-depth guide
National Borinqueneers Day
U.S. Senate Resolution 641 (2020) and subsequent federal recognition
Source-backedFixed AnnualIn-depth guide
National Make Lunch Count Day
National Day Calendar and launch-era material attribute the 2016 observance to TGI Fridays and place it on April 13.
Source-backedFixed AnnualIn-depth guide
National Silly Earring Day
Olena Kagui’s April 5, 2021 first-party founding announcement states that National Silly Earring Day is celebrated annually on April 13; National Day Archives corroborates Kagui as creator…
Source-backedFixed AnnualIn-depth guide
Thomas Jefferson's birthday
36 U.S.C. §141 requires an annual presidential proclamation inviting April 13 commemoration of Thomas Jefferson’s birthday and flag display on federal buildings. The source resolution dates…
Explore the mix
All topics →Topics represented on April 13
5 observances
All observances on this date
Source-backedFixed AnnualIn-depth guide
International FND Awareness Day
FND Hope International documents recurring International FND Awareness Day campaigns on 13 April, including the fifth annual edition in 2017 and sixth annual edition in 2018; current FND Ho…
Source-backedFixed AnnualIn-depth guide
National Borinqueneers Day
U.S. Senate Resolution 641 (2020) and subsequent federal recognition
Source-backedFixed AnnualIn-depth guide
National Make Lunch Count Day
National Day Calendar and launch-era material attribute the 2016 observance to TGI Fridays and place it on April 13.
Source-backedFixed AnnualIn-depth guide
National Silly Earring Day
Olena Kagui’s April 5, 2021 first-party founding announcement states that National Silly Earring Day is celebrated annually on April 13; National Day Archives corroborates Kagui as creator…
Source-backedFixed AnnualIn-depth guide
Thomas Jefferson's birthday
36 U.S.C. §141 requires an annual presidential proclamation inviting April 13 commemoration of Thomas Jefferson’s birthday and flag display on federal buildings. The source resolution dates…
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 →