2020
Later action
National Do Something Good for Your Neighbor Day
Designated May 16, 2020, as National Do Something Good for Your Neighbor Day within the City of Milford.
Evergreen date guide
What is celebrated on May 11?
See the observances and verified observance-history milestones attached to May 11. 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.
2010
Institutional decision
National Explosive Ordnance Disposal Day
The House Clerk roll-call record shows passage on 11 May 2010.
2006
First observance
Endangered Species Day
S. Res. 431 designated May 11, 2006, and current organizer history treats 2006 as the beginning of the annual observance.
2005
First observance
Root Canal Appreciation Day
The March 2005 launch report explicitly designates Wednesday, May 11, 2005 as the first-ever National Root Canal Appreciation Day.
1999
First observance
National Technology Day (India)
DST states that 11 May is celebrated every year and that the day has been celebrated as National Technology Day since 1999.
1950
Institutional decision
Prayer for Peace, Memorial Day
The U.S. Code source note dates the underlying Act to May 11, 1950.
1939
Reviewed depth
Other in-depth guides on May 11
Source-backedFixed AnnualIn-depth guide
Eat What You Want Day
The first-party Wellcat Holidays calendar lists Eat What You Want Day on May 11 and identifies the Wellcat holiday collection as created by Thomas and Ruth Roy.
Source-backedFixed AnnualIn-depth guide
National Technology Day (India)
India’s Department of Science and Technology identifies 11 May as National Technology Day, commemorated annually following the 1998 technology achievements.
Source-backedRule Based AnnualIn-depth guide
National Women’s Checkup Day
A 2026 New York Senate resolution identifies National Women’s Checkup Day as held annually on the second Monday in May and recognizes May 11, 2026 in conjunction with the observance.
Source-backedFixed AnnualIn-depth guide
World Ego Awareness Day
Ego Awareness Movement first-party material identifies May 11, says the movement and observance were established in 2018, and continues to steward the campaign. Reader treatment does not ad…
Explore the mix
All topics →Topics represented on May 11
4 observances
All observances on this date
Source-backedFixed AnnualIn-depth guide
Eat What You Want Day
The first-party Wellcat Holidays calendar lists Eat What You Want Day on May 11 and identifies the Wellcat holiday collection as created by Thomas and Ruth Roy.
Source-backedFixed AnnualIn-depth guide
National Technology Day (India)
India’s Department of Science and Technology identifies 11 May as National Technology Day, commemorated annually following the 1998 technology achievements.
Source-backedRule Based AnnualIn-depth guide
National Women’s Checkup Day
A 2026 New York Senate resolution identifies National Women’s Checkup Day as held annually on the second Monday in May and recognizes May 11, 2026 in conjunction with the observance.
Source-backedFixed AnnualIn-depth guide
World Ego Awareness Day
Ego Awareness Movement first-party material identifies May 11, says the movement and observance were established in 2018, and continues to steward the campaign. Reader treatment does not ad…
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 →