March 21
Let an agent handle March 21 as a calendar date with weekday computation, observances attributed to their traditions and sourced events.
Bundle → Layer → Finding → Questions Filled
4 bundles · 8 layers · 8 findings · 16 questions
Date Calendar facts.
Weekday
Computation.
Weekday
Weekday.
- On which weekday does March 21 fall in this year? measurement
- Is it a leap year? boundary
Calendar
Julian or Gregorian.
Calendar
Calendar system.
- Is the Julian or Gregorian calendar meant? boundary
- What is the equivalent date in the other calendar? measurement
Observances Holidays.
Holiday
Public holiday.
Holiday
Holiday status.
- Is March 21 a public holiday or observance here? provenance
- Which tradition or law sets it? provenance
Attribution
Traditions.
Attribution
Attributed observances.
- Which countries or communities observe something on this date, according to them? provenance
- Is the observance attributed rather than assumed? boundary
History Past events.
Events
On this day.
Events
Historical events.
- Which notable events happened on March 21, according to reliable sources? provenance
- Are dates given in the same calendar? boundary
Anniversaries
Recurring.
Anniversaries
Anniversaries.
- Which anniversaries fall on this date this year? provenance
- Which are round numbers? measurement
Planning Scheduling.
Countdown
Days until.
Countdown
Countdown.
- How many days until the next March 21? measurement
- From which date? definition
Work
Working day.
Work
Working day.
- Is it a working day for this organisation? provenance
- Do deadlines move? boundary
Classifiers Filled
- Family
- Thing Registry
- Category
- Cross-cutting context
- Entry kind
- thing
- Plane
- XCT
- Domain
- XCT.TME
What it is Filled
March 21, day 80 (day 81 in leap years) of the year in the Gregorian calendar, with 285 days remaining in both common and leap years. Observances on this date vary by country and tradition; it falls on or near the March equinox and is the International Day for the Elimination of Racial Discrimination and World Poetry Day.
Why it exists Filled
Let an agent handle March 21 as a calendar date with weekday computation, observances attributed to their traditions and sourced events.
Distinguishing features Filled
- The twenty-first day of March
- Weekday varies by year
- Observances vary by place
- Julian and Gregorian dates differ by 13 days in this era
What robots and AI may and may not do Filled
Must not
- Assume the March equinox always falls on March 21.
- Present Nowruz or other March 21 observances as universal or as tied to one nation alone.
- Report on-this-day events for March 21 without a source.
Only with a human decision
- Fixing a legal deadline that depends on the equinox or a March 21 holiday.
May
- Compute day-of-year and weekday for March 21 in a given year.
- List observances on March 21 by country with sources, including Nowruz where it falls on that day.
Moral aspects Filled
- New year and equinox festivals around March 21 matter to many peoples across countries.
Who is affected
- Communities celebrating Nowruz
- Calendar users
Owners Filled
Steward
Nobody owns a date; calendar and holiday authorities set observances.
Links to other meta-models Filled
parent
- Q11187254 - registry parent class
related
- March - month
- March 20 - date
- calendar date - category
- ISO 8601 - notation
What else AI and robots need to interact with it Filled
Identity and identifiers required Filled
- Vercy registry: vr.tr.march-21
- Wikidata: Q2433 (https://www.wikidata.org/wiki/Q2433)
- ISO 8601: --03-21 recurring date
Direct properties not applicable Not applicable
- day of year: 80 or 81 day - common year, leap year where different
- days remaining: 285 days
Plane XCT: no invented physical properties.
Recognition optional Filled
- Written 21 March or March 21
- ISO format --03-21
- Observances vary by country and tradition
- A date on calendars.
Capabilities and actions required Filled
- compute its weekday in a given year
- check local and international observances
- find sourced historical events
- schedule events
Hazards and failure modes required Filled
- Assuming observances are universal
- Unsourced on-this-day events
- Mixing Julian and Gregorian dates
Standards and interfaces required Filled
- ISO 8601
- National public holiday laws
Context of use required Filled
- A calendar date for scheduling, holidays and anniversaries.
- the recurring calendar date
- specific dated days in given years
Sources Filled
- Wikidata item Q2433: March 21 - identity and sense of the item
- Wikipedia: March 21 - general description of the item
Open questions
- Should dated days be separate entries?
- How should observances be linked?
- How should events be sourced?
Machine files
Provenance
thing registry research (pass 2) · unreviewed
Built from: models/things/publications/thing-q2433/spec.json